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COMPREHENSIVE 

Anatomy, Physiology, and Hygiene, 

ADAPTED FOR 

SCHOOLS, ACADEMIES, COLLEGES, 
AND FAMILIES, 

WITH INSTEUCTION ON THE EFFECTS 

OF 

STIMULANTS AND NARCOTICS, 

AND 

BRIEF DIRECTIONS FOR ILLUSTRATIVE DISSECTIONS OF MAMMALS, 
FOR ELEMENTARY WORK WITH THE MICROSCOPE, FOR 
PHYSIOLOGICAL DEMONSTRATIONS ON THE 
HUMAN BODY, AND FOR THE MAN- 
AGEMENT OF EMERGENT CASES. 



BY 



^ JOHN C. CUTTER, B.S., M.D., 

PROFESSOR OF PHYSIOLOGY AND COMPARATIVE ANATOMY IN TJHE IMPERIAL COL- 
LEGE OF AGRICULTURE, SAPPORO, JAPAN ; CONSULTING PHYSICIAN TO SAP- 
PORO KEN hospital; AUTHOR OF "LESSONS IN HYGIENE." 



WITH ONE HUNDRED AND FORTY ILLUSTRATIONS. 



SECOND EDITION. 




J. B. LlPriNCOTT COMPANY. 






Copyright, 1884, by J. B. Lippincott & Co. 




TO 



Kfjt MtmoxVi 



CALVIN CUTTER, A.M., M.D., 

AUTHOR OF A SERIES OF SCHOOL PHYSIOLOGIES, 

WHOSE LIFE WAS ONE OF SUBORDINATION OF SELF TO PUBLIC INTEREST, AND 

OF DEVOTION TO THE ADVANCEMENT OF EDUCATION, TO THE 

PROMOTION OF HYGIENE AND SANITATION, AND 

TO THE ELEVATION OF THE PEOPLE, 

THIS ELEMENTAKY SCHOOL TREATISE 

ON THE 

HUMAN BODY AND THE PRESERVATION OF HEALTH 

IS 

DEDICATED BY HIS SON. 



PEEFAOE. 



In accordance with the terms of my contract with the Imperial 
. Japanese Government, it has been my pleasure to give instruction 
in Human Anatomy, Physiology, and Hygiene to five successive 
classes of English-speaking Japanese students. Experience with 
students whose knowledge of English had been wholly acquired 
in the day-schools of the cities of the Empire led me to depend 
in Anatomy less and less upon the text-book and more and more 
upon dissections before the class, and upon demonstrations from an 
active coolie and from microscopic preparations. By this method 
it was found that the students acquired a more definite, useful, and 
retentive knowledge of the form, color, position, and relations of 
the parts and organs than from the text-book used in connection 
with English and American charts. Also by demonstrations on 
the coolie and the students many physiological facts were made 
manifest. As the students experienced great difficulty in under- 
standing the bearing of the very general statements in the sections 
of the text-books devoted to Hygiene, recourse was had to talks, 
giving concise and specific statements on the topics of air, water, 
ventilation, clothing, foods, etc. Furthermore, the question of 
Alcoholics, Tobacco, Opium, etc., had for them an intense interest, 
because of certain political and social problems of the day in the 
Far East. Their questions indicated a desire for unbiassed, definite, 
well-authenticated information concerning the effects of the use and 
abuse of stimuhmts and narcotics. As the conege authorities wore 
unable to procure a text-book containing such information, talks 
and lectures were introduced. 

One of the great objects in the study of natural science, and es- 
pecially of that of the structure and functions of the human body, 
is the cultivation of the observant faculties. A definite, though 

l'^ 5 



6 PREFACE. 

perhaps not extensive and deep, understanding of man is a most 
useful and most instructive form of knowledge. Such knowledge 
can be best acquired by observations on the living body, and, in the 
absence of subjects, by dissection of the bodies of mammals (dog, 
cat, rat, rabbit, etc.). Knowledge acquired through personal en- 
deavor with the knife, the magnifying glass, the ear, and the hand 
is more definite, more tangible, and more useful in life than that 
acquired wholly through glances at charts and illustrations and the 
memorizing of sentences. By the practical method, the chief facts 
mentioned in the dissections and the text will be well impressed on 
the mind, and a conception of the mechanisms and phenomena of 
life may be obtained. 

It has been my endeavor to make a practical treatise. The ana- 
tomical, histological, and physiological portions have been expressed 
in as direct and simple language as the nature of the subject seemed 
to admit. The directions for dissection, for microscopic work, and 
for demonstrations upon the human body have been so designed as 
to place their execution ^vithin the power of the average teachers 
in the American public schools. As far as possible the hygienic 
sections have been made concise, definite, and practical. The 
anatomy and physiology of a part have been given in contiguous 
paragraphs, rather than by a chapter upon the anatomy of a system 
followed by a chapter upon its physiology. The arrangement of 
the topics in each chapter, when the subject would admit, has been 
that which appeared most logical. The consideration of the motory 
and vocal systems was assigned to the later chapters, because of the 
intimate dependence of these systems upon the activities of the 
centres of the central nervous system. Numerous references from 
section to section have been introduced for the convenience of the 
teacher and for the assistance of the pupil. Chapter XV. has been 
designed to give, in a concise form, the best of the easily-executed 
methods of procedure in emergent cases, occurring in the school, 
in the home, in the workshop, on the road, and on the farm. The 
glossary has been made unusually full and complete, and is pro- 
vided with references to the sections, the text of which serves to 
express more fully the meaning of certain terms. Quantities have 
been expressed in terms of the metric system, the equivalents of 
the same being placed within brackets. Questions have been pro- 
vided for the sections printed in coarse type. 



PREFACE. 7 

In the compilation of this elementary treatise, the latest and 
most reliable information has been sought. The writings of many 
of the leading instructors and practitioners of Europe and America 
have been consulted, and the knowledge contained therein has been 
freely employed. In so small a work it would be manifestly out of 
place to give proper credit for each fact so derived. 

J. C. C. 

Sapporo, Japan, June, 1884. 



TO THE TEACHERS. 



Foe young scholars, iox first-course students in physiology, and for 
classes having thirty hours or less to devote to this branch of edu- 
cation, it is suggested that the entire time be confined to the study 
of the coarse-type paragraphs, and that the teacher, in the presence 
of the class, perform all dissections, all microscopic work, and all 
demonstrations as set forth in the text. For adoanced students, and 
for students who may have studied this branch before, it is suggested 
that each paragraph in each chapter be studied in the order given ; 
that the class be divided into sections of four to six students ; that 
one of each section be assigned to act as dissector or demonstrator 
for the day ; that, as far as possible, the microscopic work be done 
by the students, and that all be performed under the supervision 
of the teacher. If two consecutive school terms can be devoted to 
the subject, then it will be well to follow the course outlined for 
first-course students in the first term, and that outlined for ad- 
vanced students in the second term. 

Endeavor to make the instruction as actual as possible. Ee- 
peatedly call the attention of the pupils to the action of their own 
organs,— the heart, the conscious centre, the eye, the ear, the hand, 
etc. Familiarize them with the surface-markings and bony promi- 
nences of the body, so that they can localize arteries and the prin- 
cipal organs of the deep parts of the system. Direct especial 
attention to the weaker parts of the frame,— the temples, the supra- 
clavicular spaces, the pit of the stomach, the exposed blood-tubes, 
the joint-flexures, etc. 

The topical wzeMoc? of recitation maybe conducted from the heads 
of paragraphs. To impress better upon the minds of the pupils 
the ideas expressed in the illustrations and diagrams, it is suggested 
that they be required to trace outlines of the principal cuts and 
then to write upon the tracing the names of the principal parts. 



TO THE TEACHERS. 9 

In teaching anatomy, outline anatomical charts and diagrams are 
as desirable for class-room use as maps in history and geography. 

Where it is within the means of the school, I would suggest the 
advisability of purchasing a set of outline anatomical charts ; also 
a set of Bock-steger models of the special sense organs, of a wired 
French skeleton, and of a manikin made in papier-mache by Au- 
zoux, of Paris. These latter, when imported for school use, are not 
dutiable at the custom-house. J. B. Lippincott & Co., Philadel- 
phia, will furnish descriptive price-lists for the latter on application. 

Dissecting Instruments. — For the purpose of illustrative mammalian dissection, the 
student needs two or more scalpels, though crude work may be done with a sharp pocket- 
knife and a pair of Coxeter's dissecting forceps. The school will need, for occasional 
use, dissecting scissors, a meat saw, a cold-chisel, and a wood mallet. If a careful arte- 
rial dissection is to be made, then an injecting syringe and tubes and a few pounds of 
fine plaster of Paris should be procured. These instruments may be procured by mail 
of J. B. Lippincott & Co., Philadelphia. 

microscopes. — For the histological work outlined in this school-book the microscope 
should have a firm, low, metal base, a jointed bar, permitting the use of the instrument 
at any angle, a roomy stage, a diaphragm, suitable illuminating features, and a coarse 
and fine adjustment. The eye-piece and objective should always be of fine quality. One 
eye-piece (A or B), one /„ or ig- objective, and one i objective is all that is required. An 
instrument combining all these features may be had in a suitable box at prices ranging 
from fifty dollars upwards. A neutral tint camera or a camera lucida, to enable the 
student to sketch from the object, should always be purchased and constantly used. 

Materials.— One dozen glass slides, ground edges, two dozen glass cover-circles, one 
bottle of Woodward's Lilac Fluid, a few watch-crystals, and a couple of small shallow 
dishes. If much work is to be done, it would be well for the school to possess a micro- 
tome and a good section-knife. The student can make from glass tubing pipettes and 
dipping tubes and mount teasing needles in handles. Provided with a fine old razor, a 
pair of fine scissors, and the above, he is equipped for elementary work. Microscopes 
and materials may be procured from J. B. Lippincott & Co., Philadelphia. 

General Directions.— (1) Kemove all dust on the lenses of the eye-piece on objective 
with a camel's-hair pencil or a bit of soft silk. (2) Avoid unnecessary rubbing of the 
lenses. (3) For artificial illumination an argand burner may be used. Sunlight reflected 
from a white cloud is the best. Avoid direct sunlight. (4) With high powers omplo)' 
the smaller holes of the diaphragm. (.'5) In focussing, run down the tube until the field- 
glass of the objective is within the focus, but not touching the cover-glass. With the 
eye at the eye-piece, run up the tube until the focus is reached. (6) Keep both eyes open 
when studying a specimen. (7) Observe the strictest neatness and the utmost cleanliness 
in work. Clean the pipettes, slides, and cover-glasses immediately after use. For this 
purpose employ water, alcohol, oil of turpentine, and occasionally mineral acids or strong 
alkalies. Keep the clean covers in 95 per cent, alcohol. 

The tissues which make up the organs and intermediate structures of nianunuls do not 
differ materially from similar tissues in man. Hence the warm-blooded animals slain 
by butchers will furnish ample fresh nuiterials for the study of Hucroscopic anatomy. 
Use only minute portions of material. Soft, recent tissues may be snipped otY with tine 



10 TO THE TEACHERS. 



or scraped from surfaces with a dull knife. With needles mounted in handles 
they may be teased out in shallow dishes containing a little water. Sometimes it is well 
to do the teasing under a |- or 1-inch lens mounted in a loop of wire, the handle of the 
wire being inserted in a vertical wooden rod, and the lens then forced into focus by press- 
ure of the forehead. After washing, the teased specimens are floated on a slide, are 
wetted with a five per cent, salt solution, covered with a slip, and examined. Cor- 
puscles, mucus, epithelia, pus, urea, etc., may be examined in their own media. 

Each histologist has his peculiar method of procedure. The larger works, especially 
Frey's, contain minute directions for preparing the various tissues. The following is a 
ready method of procedure : In four large-mouthed bottles containing alcohol the speci- 
mens may be hardened preparatory to section-cutting. In No. 1, alcohol of 45 per cent. ; 
in No. 2, alcohol of 60 per cent. ; in No. 3, alcohol of 80 per cent. ; and in No. 4, alcohol 
of 95 per cent. The cubes of tissues, each being properly labelled, are put into No. 1, 
and every fourth day changed to the next in turn. At the end of sixteen days the cubes 
in No. 4 will be ready for cutting. Embed them in mixed melted paraffin, one part, and 
pig's lard, one part, in the microtome-well. When hardened and cold, cut the mixture 
from the front and sides of the cube, and make numerous very thin sections ; or, in cold 
weather, freeze the cubes, and then, with a sharp, cold razor, in a cold room, make sec- 
tions. Keep the sections in alcohol. Remove a few sections to a little lilac solution in 
a watch-glass. After a few minutes, transfer to a solution of muriatic acid, one part, to 
95 per cent, alcohol, four parts. After a few seconds, wash in alcohol and transfer to pure 
alcohol. From here they are placed in oil of turpentine, from whence they are floated 
on the slide, covered, and examined. 

Books for Reference. — Leidy, Human Anatomy ; Gray, Human Anatomy ; Wilder, 
Animal Technology, a Guide to Dissection of the Cat ; Foster, Text-Book of Physiology, 
4th Eng. ed. ; Beale, How to Work with the Microscope ; Carpenter, On the Microscope ; 
Phin, How to Use the Microscope; Parkes, Practical Hygiene; Wilson, Hand-Book of 
Hygiene ; Huxley, Practical Biology ; Foster, Practical Physiology ; Howe, On Emer- 
gencies ; Carter, Defects of Vision ; Wilson, Healthy Skin ; Eassie, Unhealthinefs in 
Houses ; Anstie, Stimulants and Narcotics ; Anstie, Wines in Health and Disease ; Kane, 
Drugs that Enslave ; Acton, Reproductive Organs ; Pavy, On Food ; E. Smith, On Foods ; 
Maudsley, Physiology of Mind ; Ray, Mental Hygiene ; Thomas, Medical Dictionary ; 
Cutter, Anatomical Charts, 9 Plates ; Marshall, Physiological Diagrams, 11 Maps. 



OOE^TEISTTS, 



CHAPTER I. 

GENERAL REMARKS. 

PAGE 

Definitions — Parts — Organs — Tissues — Chemical Composition . . .16 

CHAPTER II. 

LIVING PROPERTIES OF THE ANATOMICAL ELEMENTS. 

Amoeba Cells — Protoplasm — Cell-Growth — Cell-Division — Growth — Gran- 
ules — Life 18 

CHAPTER III. 

THE FRAMEWORK AND ITS COVERINGS. 

Dissection — Microscopy — Bones — Skeleton — Table of Bones — Flesh — In- 
tegument — Tissues — Membrane — Skin — Epidermis — Corium — Nail — 
Hair — Sebaceous Glands — Sweat Glands — Pei'spiration — Simpson's 
Bath — Functions of Skin — Hygiene — Clothing — Cold Feet — Light — 
Bathing — Soap 22 

CHAPTER IV. 

THE CONTRACTILE AND IRRITABLE TISSUES. 

Elasticity — Striped Muscle — Unstriped Muscle — Cardiac Muscle — Ciliated 
Cells — Physiology of Muscle — White Nerve-Fibre — Remak's Nerve- 
Fibre— Nerve-Cells— Physiology of Nerve-Mechanism— Reflex Action 
— Automatism — Inhibition — Muscle and Nerve 48 

CHAPTER V. 

THE VASCULAR SYSTEM AND THE CIRCULATION. 

Dissection — Microscopy — Thorax — Heart — Dissection— Auricles— Ven- 
tricles — Valves — Heart-Ganglia — Membranes — Arteries — Capillaries — 
Veins — Table of Arteries — Ventc Cavie — Portal Vein — Pulmonic Ves- 

n 



12 CONTENTS. 



sels — Vasa Vasorum — Blood-Coagulation — Function of Blood — Course 
of Circulation — Heart-Action — Work of Heart— Inhibition — Accelera- 
tion — Heart-Sounds — Blood-Flow — Vaso-Motor Influence — Catching 
Cold — Capillary Blood-Flow — Interchange in Capillary Areas— Proofs 
of Circulation — Hygiene 56 

CHAPTER VI. 

THE RESPIRATORY APPARATUS AND RESPIRATION. 

Dissection — Thorax — Vertebrae — Ribs — Sternum — Muscles — Thoracic 
Contents — Pleura — Nasal Passages — Pharynx — Palate — Larynx — Tra- 
chea — Bronchi — Air-Cells — Mucous Membrane — Mucus — Lungs — Tho- 
racic Capacity — Thoracic Enlargement — Inspiration— Expiration — Dif- 
fusion of Gases — Respiration — Blood- Changes — Haemoglobin — Action 
of Corpuscles — Action of Oxygen — Breathing — Statistics — Hygiene — 
Nasal Breathing — Normal Air — Air-Impurities — Effects of Vitiated Air 
— Sewer-Gas — Contagia — Air-Contamination — The Home — Air-Space — 
Ventilation — Open Fire — Sleeping-Room — Consumption — Fashionable 
Compression . . . . . . . . . . . .85 

CHAPTER VII. 

FOODS. 

Plant Food — Animal Food — Definition of Food — Standard Food — Pro- 
teids — Fats — Starchy Class — Water and Salts — Accessory Foods — Diet 
for Health — Water — Milk — Cooking — Meats — Table of Values — Cereals 
— Legumens — Vegetables — Order of Richness — Fruits — Digestibility — 
Table of Digestibility — Stimulants — Tea — Coffee — Cocoa — Alcohol . 119 

CHAPTER VIII. 

THE DIGESTIVE ORGANS AND DIGESTION. 

Dissection — Microscopy — Abdomen — Pelvis — Alimentary Canal — Gland 
— Mouth — Demonstration — Teeth — Salivary Glands — Saliva — Mastica- 
tion and Insalivation — Pharynx — (Esophagus — Deglutition — Stomach 
— Gastric Juice — Action of Stomach — Small Intestine — Peristaltic Ac- 
tion — Vomiting— Large Intestine — Liver — Function of Liver — Pan- 
creas — Function of Pancreas — Changes effected in Food Stuffs in the 
Alimentary Canal — Osmose — Absorption — Lacteals — Chyle — Move- 
ments of Chyle — Summary — Hygiene — Indigestion — Quantity of Food 
—State of Food— Bad Teeth— Care of Teeth— Frequency of Eating- 
Improper Food — Aids to Dyspepsia — Prevention of Dyspepsia — Con- 
stipation 135 



CONTENTS. 13 

CHAPTEE IX. 

THE LYMPHATICS, SPLEEN, THYMUS, ETC. — THE UKINARY 

SYSTEM. 

PAGE 

Lymphatics — Vessels— Glands — Lymph — Function— Spleen — Function — 
Suprarenal Bodies — Thyroid — Thymus — Kidneys — Urine — Function 
of Kidneys — Bladder — Betention of Urine ...... 165 

CHAPTEE X. 

NUTRITION. 

Assimilation — Glycogen — Fat — Urea — The Animal Machine — Manifesta- 
tion of Force — Production of Force — Income — Outcome — The Energy 
of a Living Diet — Heat — Energy — Heat-Production — Body-Heat — 
Heat-Regulation — Excretion — Waste Products — Summary — Hygiene 
— Thirst — Appetite — Dietetics — Food-Excess — Food-Deficiency — Want 
of Food — Human Endurance — Amount of Food — Diets . . . 173 

CHAPTEE XI. 

THE NERVOUS SYSTEM. 

Dissection — Microscopy — Head — Face — Spinal Canal — Nervous System — 
Fibres — Centres — Function — Impulses — Cerebro-Spiiial System — Brain 
— Cerebrum — Functions of Superior Parts of Brain — Rapidity of Cere- 
bral Action — Functions of Superior Ganglia — Cerebellum — Spinal Cord 
— Medulla— Pons— Membranes— Functions of Inferior Parts of Brain 
— Cerebellum — Functions of Spinal Cord — Convulsions — Paralysis — 
Sensory Nerve— Motor Nerve— Cranial Nerves— Table of Cranial Nerves 
— Function of Cranial Nerves— Spinal Nerves— Sympathetic System — 
Summary — Automatic Action — Co-ordination — Habit — Hygiene — He- 
redity—Normal Blood— Stimulants and Sedatives— Alcohol— Chloral 
—Hashish— Opium— Tobacco— Regularity of Action— Mental Exercise 
— Education — Harmonious Development — Occupation — Normal Sleep 
— Work and Worry — Rest 190 

CHAPTEE Xn. 

THE SPECIAL SENSES. 

Tongue— Taste— Nasal Passages— Smell— External Ear— Middle Ear- 
Internal Ear — Sound — Functions of External and Middle Ears — Experi- 
ments — Hearing — Auditory Sensations — Dissection of Eye — Microscopy 
— Orbits — Protective Organs — P'unctions — Lachrymal Canal and Gland 



14 CONTENTS. 

PAGE 

— Conjunctiva — Functions — Eyeball — Membranes — Media and Lens — 
Functions — Experiments — Light — Refraction — Accommodation — Ex- 
periment — Mechanism of Accommodation — Experiments — Near Limit 
and Far Limit — Imperfections — Visual Sensations and Perceptions — 
Color-Blindness — After-images — Binocular Vision — Touch — Pressure 
— Temperature — Localization of Sensations — Experiments — Muscular 
Sense — Sense of Equilibrium — Hygiene — Of Tongue — Of Nostrils — Of 
External Ear — Management of the Eye: in Infancy; in Childhood; in 
Student Life ; in Adult Life — Illumination — Statistics — Myopia — Pre- 
vention of Eye-Disease — Finger-Tips 240 

CHAPTER XIII. 

THE LARYNX AND VOICE. 

Larynx— Cartilages — Cords — Production of Sound — Voice — Muscular Co- 
ordination — Speech— Hygiene ........ 284 

CHAPTER XIV. 

THE MOTOH APPARATUS AND LOCOMOTION. 

Dissection — Bone — Cartilage — Bone-Formation — Microscopic Characters 
— Joint — Synovial Sac — Synovia — Ligaments — Interarticular Carti- 
lage — Table of Muscles — Tendons of Muscles — Action of Muscles — Co- 
ordinate Movements — Sensory Influence — Progression — Effects of Ex- 
ercise — Deficiency of Exercise — Systematic Exercise — Hygiene — Phys- 
ical Culture — Swedish, English, and German Systems — Influence of 
Physical Culture — Suppression of By-Motions — Conditions for Exercise 
— Rest — Kinds of Exercise — Amount of Exercise — Posture — Training. 293 

CHAPTER XV. 

CARE OF THE SICK AND EMERGENT CASES. 

Care of the Sick — The AVatcher — Poisons — Table of Poisons and Common 
Antidotes — Emergent Cases — Bleeding — Flesh-Wounds — Bleeding at 
the Nose — Broken Bones — Burns and Scalds — Asphyxia : from Drown- 
ing ; from Illuminating Gas — Silvester's Method — Prevention of Drown- 
ing — Bodies in External Ear — Particles on the Surface of Eyeball — 
Frost-Bite — Hernia — Retention — Simpson's Bath — Wounds : Punc- 
tured, Mad Dog, Serpent, and Insect — Ivy- Poison — Sunstroke . . 326 

GLOSSARY 345 

INDEX 369 



Amtomy, Physiology, and Hygiene. 



CHAPTER I. 

GENEKAL EEMAKKS. 

1. Anatomy is the science of organization. Human 
anatomy treats of the number, shape, situation, structure, 
and connection of the parts making up man. Histology 
considers the minute structure of the tissues as made known 
by microscopic and microchemic studies. Physiology 
treats of the healthy operations which take place in living 
beings. Hygiene embraces a consideration of the condi- 
tions most favorable for the healthy action of the parts 
and of the whole. Chemistry treats of the nature and 
properties of every object accessible to man. 

2. The body of man, as a whole, is readily seen to be 
composed of the head, neck, trunk, and extremities. These, 
under closer examination, offer the scalp, forehead, eyes, 
ears, nose, and mouth, of the head ; the thorax, the abdomen^ 
and the pelvis, of the trunk ; the arm, forearm, wrist, and 
hands, of the upper extremity; the thigh, leg, ankle, and 
foot, of the lower. It is seen that different materials are 
employed in the construction of the varying parts, as skin, 
hair, nails, and teeth ; that some parts are soft (fat), others 
firm (muscles), and still others hard and resisting (bone). 



1. Define Anatomy, IIistolog3\ Physiology. Hygiene. Chemistry. 

2. Give the general divisions of the body. Subdivisions of the 
head. Of the trunk. Of the extremities. jMaterials employoil. 

15 



16 ANATOMY^ PHYSIOLOGY, AND HYGIENE. 

3. If the dead body be examined, it will be found to 
consist of a number of differing parts, called organs (such 
as the heart, brain); that the organs are made up of a 
limited number of materials, called tissues (like connective, 
nerve, muscular tissues) ; that the most complex organs are 
constructed of less than a dozen tissues, combined in vary- 
ing numbers and proportions ; and that the tissues are built 
up of cells and granules. 

Demonstration. — Point out on the bodj' of a boy the parts mentioned in paragraph 2. 
■Request several of the students to demonstrate the same later. Bring into the class the 
heart of a chicken, calf, or pig. State its functions to the class. Show that it is made 
up of a number of materials, as of muscle, of areolar connective tissue, of nerve-masses, 
of blood-tubes, of white fibrous tissue, etc. Snip a small bit of areolar tissue. Under 
water, in a shallow saucer, tease it out with needles inserted in handles. Place on a 
slide in a drop of water under a cover-glass. Call attention to the membrane, or ex- 
pansion, as a whole ; then to the component fibres. If there are a few fat cells present, 
call attention to their form and limiting membrane. Then press on the cover and ex- 
amine the oil-globules. 

Place a drop of yeast on the slide. Spread out thin and cover. Call attention to the 
cells and groups of vegetable cells, their sacs, the contained protoplasm often showing a 
few shining dots. Run in a drop of magenta solution. The protoplasm will be stained. 

4. Chemical Composition. — The normal body includes 
only fourteen chemical elements in its composition : oxy- 
gen, O ; hydrogen, H ; nitrogen, N ; carbon, C ; sulphur, 
S; phosphorus, P; fluorine, Fl ; chlorine, CI; Sodium, 
Na; potassium, K; calcium, Ca; magnesium, Mg; sili- 
con. Si; and iron, Fe. Carbon, by weight, forms the 
principal element. It is the base of all organic substances. 
It is the chemical bond of all the various atoms which 
enter into the composition of the granules, cells, and tis- 
sues. The gases oxygen and nitrogen often are found in 
the tissues in a free state. 



3. What makes up the body? Examples. Make-up of organs? 
Make-up of tissues ? How many ? 

4. Name the chemical elements. What of carbon? Of oxygen? 
Of nitrogen^ 



GENERAL REMARKS. 17 

5. In the living organism these fourteen elements are 
united into a series of complex chemical compounds. 
Owing to the presence of nitrogen in proportionably 
larger amounts than in plants, there is in the animal or- 
ganism a great degree of chemical complexity and insta- 
bility. The latter is shown in the quicker decay of animal 
tissues over vegetable tissues when once removed from the 
living organism, and the former by the marked predomi- 
nance of ternary compounds (C, H, O) over proteid com- 
pounds (C, H, O, N, S, P) in the plant. 

5. What of these elements ? The difference between animal and 
vegetable compounds ? Define proteid. (See Glossary.) 



2* 



CHAPTER IT. 

LIVING PROPERTIES OF THE ANATOMICAL UNITS. 

Demonstration. — Amoeba. Secure some stagnant water, or ooze from a pool, or make 
an infusion of animal matter and allow it to evaporate under direct sunlight. Search in 
the same for jelly-like organisms. Place one on a slide in a drop of water. Call atten- 
tion to the outline, and to the structure, the nucleus, the contractile vesicle, the contained 
materials, the movements, and the formation of pseudo-podium. 

6. The Amceba is a microscopic mass of living matter which 
inhabits fresh water. It is composed of jelly-like protoplasm con- 
taining granules. Its outer portion consists of a slightly consoli- 
dated transparent layer, and its inner portion of a more fluid, more 
mobile substance. The outer layer is highly extensile and contrac- 
tile. The i3seudo-podia (having false feet) are mainly made up of 
this layer. The inner portion contains the " nucleus," "contractile 
vesicle," and, at times, " food vacuoles." Food may be taken at any 
part of the surface and expelled from any part, after which the 
aperture closes up. There are no digestive, secreting, or excreting 
organs. There are no traces of a nervous system or of sense organs. 
The general surface recognizes contact with other objects. The 
mass moves itself by projecting out blunt finger-like processes, 
called pseudo-podia. These are projected at will from any part of 
the surface, and may be withdrawn at will. The nucleus appears 
at times as a clear granular body, or as a clear vesicle containing a 
nucleolus. New mrfmc?wa?s are produced in several ways: 1. The 
organism may undergo self-division, each part becoming indepen- 
dent (Fig. 1, C). 2. A pseudo-podium may become detached and 
develop into an amoeba. 3. A new mass may be produced in the 
interior, which may or may not be set free, but which develops into 
a perfect amoeba (Fig. 1, B). 

7. This little mass performs all the offices necessary to its grade 
of life, — growth and reproduction. This little mass is contractile, — 

18 



LIVING PROPERTIES OF THE ANATOMICAL UNITS. 19 

that is, it exhibits motion in its interior, as well as from place to 
place ; it is irritable and automatic, for when disturbed it can move 
at will from its position ; it is receptive, for it takes in food ; it is 
assimilative, for out of the materials taken in it transforms and 
accepts a portion, and increases in size ; it is respiratory, for gases 
interchange between it and its watery home ; it is undergoing in- 
ternal changes, and secretes, excretes, and rejects certain products ; 
it is reproductive. In brief, all the major phenomena of life are 
exhibited in the amoeba. All the physiologic phenomena of all the 

Fig. 1. 




Fig. 1. — Amoeba SPHyEROCoccus (Letourneau). A, Amoeba encysted; protoplasmic 
mass (c) containing nucleus (6) and nucleolus (a) ; enveloping membrane (d). B, Amoeba 
free from enveloping membrane. C, Amoeba commencing to divide. Da and Db, totally 
divided into two independent amoebae. 

higher animals are but the working out of certain acts by similar 
protoplasmic efforts. In the amoeba grade of organization all is 
done by the protoplasmic units. In the higher grade of organisms 
there is division of labor, differentiation of duties. The many tis- 
sues and organs of the higher grades, like the simple mass of the 
lowest, work for a common purpose, — the building up, the protect- 
ing, the developing of the organism, and the continuance of the 
species. 

8. Cells. — The smallest known masses of living matter assume 
the spherical form. They present a colorless, soft, and, at times, 
granular a})pearance. Within the mass may be seen a clear, dis- 
tinct, non-granular part or body, often enclosing, in turn, a still 
smaller body. Occasionally a thin layer of hardened material may 
be seen on its surftice. The size of the masses is about 0.012 milli- 
metre (vjn^o^ of an inch) in diameter. This is [)re-enniuMitly the 



20 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

anatomical unit, and is known at present as the cell. The central 
mass is called the cell-body ; the embedded, non-granular part, the 
nucleus ; the body within the nucleus, the nucleolus ; and the limit- 
ing layer, the cell-wall. By the activities inherent in the cell-body 
the food or pabulum received is converted into new cell-body mate- 
rial, which is later resolved into formed material, as cell-wall, fibres, 
tissues. All the formed or histological materials of the tissues pass 
through the cell-body stage of growth. The white corpuscle of the 
blood exhibits most of the characters, histological and physiological, 
of the anatomical unit (113). 

9. Protoplasm. — The cell-body in the living state consists of a 
colorless, structureless material, which exhibits, under the micro- 
scope, slow movements. These movements originate in this trans- 
parent material ; this material is called Protoplasm (or Bioplasm). 
The granular contents which are seen moving about in the mass are 
only minute suspended matters. The actual chemical composition 
of protoplasm is not known, because the processes of chemistry em- 
ployed in the analysis destroy the vital or living feature, which is 
the marked characteiustic of protoplasm. It probably contains fats, 
carbo-hydrates, proteids combined with certain inorganic salts, and 
much water. Protoplasm can absorb, excrete, secrete, grow, move, 
and multiply. The functions of the granules and nuclei have not yet 
been determined. Protoplasm is most easily studied in one of the 
simplest of the animal series, — the Amoeba. Human white blood 
and mucous corpuscles also show a part of the above phenomena. 

10. Cell-Growth. — Each living cell-body possesses the power of 
receiving into itself /ooc?s, — i.e., materials different from itself, — in 
solution or in a state of fine division, and of working chemical and 
physical changes in the same until they become part and parcel of 
the cell-body. The matters received acquire properties and powers 
which the food alone did not have. The new matter is added to 
the mass not upon the outside, but in the inside, — ^that is, by intus- 
susception. Cell-growth is an epitome of tissue growth, of organ- 
growth, of body-growth. 

11. Cell-Division. — If the materials received into the cell-body 
are in excess of its wants, and if it attains its limits of gro^\'th, then 
the formation of new living centres is induced. This tendency for 
change may come from within or firom without. From without, it 
may start in an hour glass-like contraction or elongation, with con- 



LIVING PROPERTIES OF THE ANATOMICAL UNITS. 21 

traction of the cell-body continuing to the point of dividing the 
mass into two parts (Fig. 1, D) ; from within, by the appearance 
in the interior of the parent cell of one or more cell-bodies which 
may or may not be set free (Fig. 1, B). The new cells possess the 
properties and tendencies of the parent cells. In most cases the 
nucleus divides earlier than the cell-body. 

12. Growth. — The increase in volume of the anatomical ele- 
ments, together with their multiplication, accounts for the increase 
in size in tissues, organs, and the body, — that is, growth. The 
rapidity and energy of growth vary with the cell-body, its con- 
dition, its surroundings, and its food-supplies. 

13. The GRANULES are the smallest known histologic elements. 
They may be suspended in fluids, may remain free with certain 
chemical elements, or perhaps enclosed in cells. They may be pro- 
teid or fatty in their nature. They vary as to color, size, and den- 
sity. Their ofiices are not well understood : possibly they are food 
not yet ready to be made into the cell-body and the tissues. 

14. In the living body, as in the living cell, there is a ceaseless 
internal motion and change of material. There is a constant re- 
moval of old or used materials, and a constant taking in of new 
materials, which are changed and modified in the organism, and 
then enter into its structure. The cessation of these changes in 
the cells or tissues constitutes local death ; in the entire organism, 
death. The phenomena of life appear to imply the presence in 
the organism of a guiding, controlling, and dictating force. This 
force is modified in many ways by external and internal condi- 
tions; it is transmitted from generation to generation, and it 
appears distinct from, though working with, the common physical 
forces of nature. To this force have been applied the terms " germ 
force" and ''vital force." 



CHAPTER III. 

THE FKAMEWOEK AND ITS COVERINGS. 
Direction for Dissecting. 

Take the hind leg of a sheep, rabbit, dog, or rat. On the inside of the thigh make a 
clean cut from tlie groin to the second joint through the skin down to the muscle. This 
exposes, in section, the hairs, and their place of implantation, the sMn. Now dissect off 
the skin to the right and left of the line, and remove it from the leg. We find the skin 
is attached to the parts beneath by a loose, extensible, elastic web, the areolar or con- 
nective tissue. In this loose web we find masses of fat, making up a more or less firm 
layer. Remove this. The white, glistening, membranous surface of the fascia is pre- 
sented. This holds the red flesh-bands in their proper position. Make an incision 
through this, and dissect it ofi'. The fleshy muscles and thin, white, firm tendons of con- 
nection come into view. With the handle of the knife, or the back of the blade, sepa- 
i-ate two of the large muscles, and we find that areolar tissue and a firmer intermuscular 
connective tissue or septum bind them together. In the gap, or an adjacent one, may 
be seen a whip-cord-like, hollow tube, the artery, one or two thinner, dark-colored, par- 
allel tubes, the veins, and a clean, white, smooth cord, the nerve. Near the groin, and in 
the vicinity of the veins, may be seen a few roundish, softish, dark, pea-sized bodies, the 
lymphatic glands. 

Remove the flesh from the bones. The bones will be found to be covered by a firm, 
white, close-fitting membrane, the periosteum. Beneath the periosteum may be seen a 
number of pits and holes. These admit microscopic blood-vessels to the interior. Break 
or saw the bone. At the line of fracture will be seen the frayed edge of the periosteum, 
the hard, pinkish white surface of the bone, and the spongy interior filled with a reddish, 
fatty matter, the medulla or mun-ow. 

The joint. Remove the bits of fat, muscle, and areolar tissue. The bones will be seen 
to be held together by hard, firm, inelastic, flexible bands, the ligaments. These liga- 
ments may be broad and flat, ribbon-like or round. Cut the ligaments and open the 
joint. A white, glairy fluid, the synovia, escapes. The ends of the bones are found 
tipped with a pearl j-^ white substance, a shaving of which can be removed by the knife. 
This is cartilage. Loose pieces of cartilage and internal ligaments may be seen within 
the joint, which is lined by the smooth synovial membrane. 

Microscope Work. — Of the soft parts, — muscle, tendon, areolar tissue, etc., — cut cubes 
about three-quarters of an inch on a side, and place in alcohol of one per cent, for hard- 
ening purposes. Take a small bit of areolar tissue or muscle, etc., place on a clean slide, 
add a drop or two of water, and carefully tease out with the needles. Do not hesitate 
to spend much time in the teasing. Breathe on the lower side of a cover-glass, apply 
the glass and adjust it in place, then place the slide on the stage and examine. Or take 
a drop of the fluids, — serum, blood, mucus, synovia, etc., — as they occur, on a clean 
slide ; put on a cover-glass ; by slight pressure spread the drop, and examine by trans- 
mitted, by oblique, by direct light. Also observe the changes in form produced by slight 
changes of the focus, especially in examining the blood-corpuscles. 
22 



THE FRAMEWORK AND ITS COVERINGS. 23 



The Framework. 

15. The framework of the human body consists of the 
boneSj which, taken together, constitute the skeleton. 

16. The BONES (501), when in the body, are moist, 
pinkish white in color, and covered with a tough, closely- 
adherent membrane, called the 'periosteum {'peri, around, 
osteon, bone). The surface of bones is hard and compact. 
On the surface are many little holes, which lead to the in- 
terior. The interior usually has a spongy appearance. The 
spongy spaces chiefly contain a soft, reddish, fatty material, 
called marrow, or medulla. 

17. The SKELETON gives general form to the body. It 
determines the height and the breadth; it supports and 
protects the soft parts of the interior ; it gives eifect and 
precision to the actions of the muscles, or ruddy flesh. Its 
separate pieces, two hundred in number (Gray), are held 
together by moist, strong, non-elastic, flexible bands, called 
ligaments (Fig. 2). The skeleton constitutes about sixteen 
per cent, of the body-weight. 

18. The FLESH constitutes the soft, red portions of the 
body. It covers over in general the bones, and is attached 
to their surfaces at certain definite points. This skeleton- 
surrounding mass consists of about three hundred and sev- 
enty distinct fleshy masses, called muscles (75, 76). They 
are usually arranged in pairs. Their shape, size, form, and 
arrangement depend on the outline of the skeleton. They 

15. Speak of the skeleton. 

16. The appearance of a fresh bone. The surface. The interior. 
The periosteum. The marrow. 

17. Use of the skeleton. Number of bones. Ligaments and their 
uses. Skeleton percentage of the body-weight. 

18. Speak of the flesh. How many muscles? How arranged? 



24 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Fig. 2. 




THE FRAMEWORK AND ITS COVERINGS. 



25 



TABLE OF THE BONES, 

Frontal (forehead). 



Head (22) 



Skull (S). 



L Face (14) 



Cervical Eegion (8) 



Thorax (37) i 12 Dorsal Vertebrae (back). 

Sternum. 



2 Temporal (temples). 

2 Parietal (side). 

Occipital (posterior base). 

Sphenoid (base). 

Ethmoid (base of nose). 

2 Superior Maxill* (upper jaw). 

2 Nasal (bridge of nose). 

2 Malar (cheek). 

2 Lachrymal (corner of orbit). 

2 Turbinated (within nostrils). 

2 Palate (posterior hard palate). 

Vomer (nasal partition). 

Inferior Maxilla (lower jaw). 

7 Cervical Vertebriie (neck). 

Hyoid Bone (base of tongue). 

14 True, G False, 4 Floating Ribs. 



Shoulder 



Hand 



Upper Extremities (64) 



Lumbar Region (5) 



_ , ,2 Innominata. 

Pelvis (4) } „ 

^ ' i Sacrum. 

Coccyx. 

Tldgh . . . 



/ Clavicle (collar). 

<- Scapula (shoulder-blade). 

f Humerus (arm). 

<■ Radius, Ulna (fore-arm). 

r 8 Carpal (wrist). 

^ 5 Metacarpal (hand), 

[ 14 Phalanges (fingers). 



5 Lumbar Vertebrae (loins). 



Lower Extremities (60) 



Leg 



Foot 



Femur. 

Patella (knee-pan). 
Tibia (large bono). 
Fibula (outer bono). 
7 Tarsal (instop, heel), 
5 Metatarsal (arch). 
14 Phalanges (toes). 



26 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



are arranged in layers, some deep, some superficial. On the 
back and abdomen they are broad; on the extremities, long 
and narrow ; about openings, circular. 

19. All muscles are held in their proper places by a 



Fig. 3. 





Fig. 3. A Diagrammatic Vertical Section of the Normal Skin.— a, The Horny 
stratum of the epidermis, h. The Lucid stratum, and c, The Granular stratum, — both 
thin, and together forming the middle layer of the epidermis, d. The Soft, or Mucous, 
layer, of the epidermis, which includes the skin pigment, e. The Corium, or dermis 
(called also cutis vera, or true skin), and its papillae. /, Tactile coipuscle. jr. Sebaceous 
gland, fe, Erector-of-the-hair muscle, i, Hair root, j, Pacinian corpuscle. A-, Perspira- 
tory gland, showing the duct, which becomes spiral towards its outlet on the surface of 
the skin. I, Subcutaneous connective tissue. 

moist, whitish, web-like structure, called inter-muscular 
connective tissue. Muscles, being made up largely of mus- 
cular fibre (71), are endowed with the power of contractility, 
— that is, under certain stimulants (as heat, pinching, elec- 
tricity, nerv^e-cell influence) the fibre becomes shorter, and 
on the removal of the stimulant regains its former state. 

19. How are muscles held in place? Of what composed? Give an 
endowment of the muscles. Name some stimulants of the muscles. 
Muscular percentage of the bodj^-weight. 



THE FRAMEWOKK AND ITS COVERINGS. 



27 



The muscles of an adult (thirty- one years of age) consti- 
tute about forty-two per cent, of the body-weight. 

20. The Integument. Outside of the white, firm, re- 
sisting membrane called fascia, which holds many of the 



Fig. 4. 



Fig. 5. 





Fig. 4 (Leidy). Portion of Connective Tissue from the axilla, exhibiting its composi- 
tion of bundles and filaments of fibrous tissue crossing in every direction. The rounded 
bodies represent a single row and a portion of small groups of fat cells. Magnified. 

Fig. 5 (Leidy). 1, Portion of Connectivk Tissue from that which envelops the flexor 
tendons of the fingers as they pass beneath the annular ligament, treated with acetic 
acid. The pale, dotted portion is intended to represent the fibrous element fading away ; 
the blacker, tortuous lines and nets rei)resent the mixture of elastic tissue. 

outer muscles of the body and limbs in position, is a layer 
or two of moist, fine, web- like areolar or connective tissue. 
In the meshes of the latter are seen little masses of semi- 
fluid fat. Outside of those layers, and intimately connected 
with them, is the sJdn. 

21. The areolar tissue, the fat, and the skin, together, 
round off, fill up, and finish the contour of tlie whole 
surface of the body. The fat under the skin accumulates 
more rapidly than any other tissue, and is the earliest 

20. What is fascia ? Give its function. Speak of the areolar tissue. 
Where is the skin found? 

21. What gives finish to the outlines of the hody ? Speak of fat. 
Its abundance. 



28 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



removed under disease. It is a storehouse of food, and a 
good heat-retainer for the body. It is more abundant in 
children and in females than in males or in adults. 

22. Areolar connective tissue consists of bands of white, also of 
yellow, elastic fibres, which interweave in every direction, leaving 
meshes or open spaces. It is loose, moist, flexible, and extensible. 
Its series of open spaces communicate with adjacent spaces, and so 

Pig. 7. 




!/'.'#;(( 



m*x 



Tig. 6 (Leidy). Fibrous Tissue.— 1, Portion of tendon, exhibiting its composition of 
prismatic bundles of fibrous tissue, the filaments all parallel to one another. 2, A few 
bundles drawn from the others, exhibiting their union by delicate crossing filaments of 
connective tissue. 3, One of the varieties of fibrous tissue. 4, A single bundle, more 
highly magnified, with a portion (5) of the filaments fretted out. 

Fig. 7 {Leidy). Elastic Tissue. Highly magnified. 

on throughout the body. In these meshes are lodged the fatty tis- 
sues. In these spaces accumulate the fluids in general dropsy of 
the subcutaneous parts of the body. The function of this tissue is 
to connect organs and parts of organs, to support blood-vessels, 
lymphatics, and nerves, and to allow limited motion to adjacent 
muscles or organs. 

23. The ichite fibrous tissue consists of fine white fibrils, usually 
arranged in parallel lines in the form of small bundles. It has a 
shining aspect, and is firm, resistant, and not elastic. It enters into 
the formation of membranes, tendons, and ligaments. 

24. The elastic tissue has a yellow color. Its fibres are never quite 
parallel to one another, but often branch out and unite again. When 
cut, the ends of these fibres curl up. After this tissue has been 
stretched, it retracts like an india-rubber band. It is found in the 



THE FRAMEWORK AND ITS COVERINGS. 



29 



areolar tissue, in the inner coats of the arteries, in certain ligaments 
of the spine, and in the vocal cords. 

25. Adipose tissue, or fat (309), is composed of numerous round or 
ovoid sacs, filled with an- oily fluid. At the temperature of the 
living body the fat is fluid, but after the cooling of the body it be- 
comes quite solid. In the state of emaciation the fat vesicles are 
emptied of fat, and the walls become shrivelled. This tissue is not 
formed within the skull, in the lungs, or in the eyelids, because its 



Fig. 8. 



Fig. 





8 {Leidy). Cuussung Bands of fibrous connective tissue. 
Fig. 9 (Leidj/). Adipose Tissue, with Connective Tissue, from the superficial fascia 
of the abdomen. Highly magnified. The groups of fat vesicles are observed contained 
in the meshes of connective tissue. 



accumulation alternating with its diminution would interfere with 
the functions of those organs. It is found under the skin (subcuta- 
neous fat), about the kidneys, about the joints, about the heart, in 
the orbits, and in the omentum (21). 

26. Membrane is the name given to the thin, supple, more or loss 
elastic webs of the body. These Avebs are intended to separate, to 
envelop, or to form organs, or to bear certain celhilar structures, 
called epithelia (156). The membranes are of three \i\\\*\^,—Jibrous, 
serous, and mucous. 

8* 



30 ANATOMY, PHYSIOLOGY, AIS^D HYGIENE. 

27. The fibrous membrane is firm, resisting, slightly elastic, white, 
sometimes pearly and glistening. It is made up largely of white 
fibrous tissue, though containing a slight admixture of yellow 
elastic fibre. It is sparingly supplied with blood-vessels and nerve- 
fibres. Its functions are to suiTOund organs and to augment their 
solidity, like the capsule of the kidney, the sclerotica of the eye; 
to retain muscles in their proper positions, as the fasciae of the 
arms and limbs ; and to favor the motions of tendons and of the 
skin. 

The serous membrane. (See 156.) 

The mucous membrane. (See 164.) 



The Skin. 

28. The Skin is -the covering which invests the body. 
It is a flexible, extensible, elastic membrane. It is soft, 
smooth, and has an oily feel. Upon its surface, lines, pits, 
and depressions, and projecting hairs, may be seen. It 
varies in thickness, being thickest on the back, the palms, 
and the soles. 

The skin consists of an external layer having no blood- 
vessels, the epidermis, and an internal deeper layer having 
many nerves, numerous blood-vessels and lymphatics, the 
Gorium, called also the dermis. The corium is the most 
important structure of the integument. In the deepest 
layers of the epidermis are soft cells in which the pigment, 
giving color to the skin, is deposited. A blister is an ac- 
cumulation of fluid between the epidermis and the corium, 
causing the former to be raised from its bed. 

29. The Epidermis, or Cuticle, is made up of layer upon layer 
of nucleated and non-nucleated cells. The cells of the external or 
upper layer are flattened, dry, firmly adherent, and transparent. 
This is known as the horny layer. The cells in the deeper layers 

28. What is the skin? Speak of its laj-ers. Where are pigment 
cells found ? What is a blister ? 



THE FRAMEWORK AND ITS COVERINGS. 



31 



Fig 




resting on the corium are soft, granular, delicate, and nucleated, 
but have no cell-wall. This is called the Rete Mucosum, or soft 
epidermis. The epidermis is sup- 
plied with nervous filaments termi- 
nating in club-shaped extremities. 
In the deepest cells of this layer 
is deposited the pigment, which, 
varying in amount from the mini- 
mum in the Scandinavian to the 
maximum in the Guinea negro, 
gives color to the otherwise pink- 
white skin of health. The pigment 
in most skins, by exposure to the 
sun, becomes darker. The freckle 
consists of a circumscribed, in- 
creased amount of normal pigment. 
30. The ComuM, or True Skin, 
lies beneath the rete mucosum. It 
is a dense, moist, tough, and flexi- 
ble web of fibrous and areolar tis- 
sue, and is of a pinkish- white color 
in all races. In this structure are 
found abundant blood-vessels and 
nerves, lymphatics, smooth mus- 
cles, hairs, oil glands, sweat glands, 
and fat cells. The upper portion 
of the corium is called the papil- 
lary layer, and consists of little 
conical projections, called papillce 
(Fig. 10). These are most per- 
fectly developed on the tips and 
inner surface of the fingers. They 
are of two kinds, the. vascular and 
the sensory. The latter receive less 
blood than the former, but are largely mudo up of nervous olcMnents, 




Fig. 10 {Leicltj). Vertical Section of 
THE Skin of the Forefinger across 
Two of the Ridges of the Surface; 
highly magnified. 1, Dermis, composed 
of an intcrtexture of bundles of fibrous 
tissue. 2, Epidermis. 3, Horny layer. 
4, Soft layer. 5, Subcutaneous connective 
and adipose tissue. 6, Tactile pupilhv. 
7, Sweat glands. 8, Puct. 9, Spiral 
liassage from the latter through the epi- 
donnis. 10, Termination of the passage 
on the summit of ridge. 



31. During life the upper layers of the epidermis 



s are 



31. Changes of the epidermis. Row aftoetod in soaUls ami scarla- 
tina? How is the callus made? How are corns produced ? 



32 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



EiG. 11. 




Fig. 11 (Leidy). Scurf from the 
Leg. — A fragment of scurf, consist- 
ing of dried, flattened, non-nucleated 
cells. 2, A few cells with a nucleus. 
3, A cell more highly magnified, to 
exhibit its polyhedral fonn. 



being constantly worn off and as constantly replaced by 
the layers growing up from beneath. In scarlatina, and 

after scalds, the entire epidermis, 
as of the hand, may come off in 
large flakes or as a complete 
glove. If the skin is exposed 
to constant, moderate friction, 
then the epidermis may thicken, 
and a callus is formed. If the 
friction and the pressure take 
place over a limited portion of 
the toes, a hard, circumscribed 
growth of the epidermis is 
formed in the shape of a cone 
with the base upward. The pain 
is produced by the core of this growth, called a corn, press- 
ing on the sensitive structures of the true skin. 

32. If the epidermis is removed, as by a blister, then it 
will soon be restored to health. If the irritant or injury 
acts deeply enough to destroy the corium, then normal re- 
pair will not take place. The skin will be replaced by con- 
nective tissue, and a scar, or cicatrix, will remain. In large 
surface wounds, the surgeon often hastens repair and dimin- 
ishes the tendency to the formation of a large scar by 
transplanting small bits of skin from healthy persons to 
the large denuded surface. Occasionally large bits of skin 
are transferred from one part of the body to another. 

33. The NAIL is a modified part of the epidermis. It 
is horny, flexible, and translucent. It grows in length by 



32. Give the effects of injury to the epidermis. To the corium. 
"What causes a scar ? "What is transplanting skin ? Its value ? 

33. Give the structure of the nail. Its formation. 



THE FRAMEWORK AND ITS COVERINGS. 



33 



Fig. 12. 




additions at the root, in thickness by additions to the under 
surface. Its function is to protect the sensitive tips and to 
aid in seizing small objects. 

34. The nail is continuous with the epidermis at the root and 
near the tip. The corium, on which the nail rests, is called the 
bed or matrix. The nail is made 
up of closely-connected plates con- 
taining nucleated fat cells. The 
matrix is very vascular, and the 
nail grows rapidly as long as the 
matrix is healthy. 

35. In-grown nails usually 
result from boot-pressure from 
the outside, or the collecting 
of hard materials between the 
nail and the skin. Remove 
the cause. Clean the parts. 
Insert a little pledget of cotton or lint under the sharp edge 
of the nail, to keep it from the inflamed parts. In cutting 
the toe-nails, leave the nail square. The corners should 
not be rounded. 

36. The Hairs have their seat in pits in the skin, 
called hair follicles. The hair root grows upon a pointed 
protuberance in the base of the follicle, called the pa- 
pilla. The hair shaft is that portion of the hair projecting 
above the skin. In the Europeans, it is oval in cross- 
section; in the Japanese and Chinese, it is circular. Its 
length varies greatly. Hairs occur on most parts of the 
body, as is very evident in the Ainos, or hairy men of 
Japan. 



Fig. 12. A Section of the End of 
THE Finger and Nail. — i. Section of 
the last bone of the linger. 5, Fat, 
forming the cushion at the end of the 
finger. 2, The nail. 1, 1, The cuticle 
continued under and around the root 
of the nail, at 3, 3, 3. 



35. Cause of in-grown nails. Managoinont. Tlio outtini:: of n:iils. 

36. What are hair follicles? What is the papilla? The shaft? 
Give the shape, length, and distribution of hairs. 

c 



34 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



37. The hairs are usually seated obliquely in the skin, 
but their free ends are often elevated by shortening of the 




Fig. 13 (Lekhj). Diagram of Struc- 
ture OF THE EOOT OF A HaIR WITHIN 

ITS Follicle.— 1, Hair papilla. 2, 
Capillary vessel. 3, Nerve-fibres. 4, 
Fibrous wall of the hair follicle. 5, 
Basement membrane. 6, Soft epider- 
mic lining of the follicle. 7, Its elastic 
cuticular layer. 8, Cuticle of the hair. 
9, Cortical substance. 10, Medullary 
substance. 11, Bull) of the hair, com- 
posed of soft polyhedral cells. 12, 
Transition of the latter into the cor- 
tical substance, medullary substance, 
and cuticle of the hair. 



Fig. 14. 



Fig. 14 {Leichj). PORTION OF A 
Hair from the Outer Part of 
THE Thigh, magnified. 1, Shaft 
of the hair, covered with trans- 
verse markings indicating the 
projecting edges of the cuticular 
scales. 2, Cortical substance at 
the end of the hair, broken up 
into coarse fibres, as the result of 
friction of the clothing. 



little muscles in the skin. It is estimated that the normal 
scalp contains about one hundred and tAventy thousand 



37. How are hairs seated? Their number in the scalp? Color? 
Growth ? Their function ? 



THE FRAMEWORK AND ITS COVERINGS. 35 

hairs. The numbers on the body vary with the locality, 
the person, and the race. The color depends on the pres- 
ence of granular pigments. Hairs are nourished from the 
papillae. They grow only in length. When cut off, if the 
papillae be healthy, they soon grow out to their determinate 
length. Their function is protection. 

88. The hair follicle is a minute depression of the epidermis and 
corium. At its base rises a conical, smooth body, a growth from the 
mucous layer, which is seen to extend into the base of the hair. 
This is the papilla of the hair, and into it enter blood-vessels and 
nerves. Upon this grows the hair bulb or root. The shaft consists 
of long, spindle-shaped, flattened filaments, striped longitudinally, 
which contain pigment granules. The filaments are bound together 
by a delicate investing membrane, called cuticle. The cuticle has 
a crossed, laminated appearance, not unlike the scales on a fish. 
The free ends of the scales point to the tapering free ends of the 
hair. On most hairs, a line of colored cells, called the medullary 
substance, runs lengthwise through the centre of the hair. Kaposi 
maintains that the accredited accounts of persons whose hair has 
changed color suddenly, under the influence of fear or other strong 
emotion, must all be rejected, since such changes are physiologically 
impossible. 

39. The small flat muscles of the hair are inserted obliquely into 
the hair follicles below the ducts of the oil glands. The contrac- 
tion of the muscles causes the oblique-lying hairs to become erect. 
Hairs are strong, extensible, and elastic. They absorb and give 
off" water readily. Hairs consist of a nitrogenous substance con- 
taining sulphur, fats, and salts. 

40. Superfluous haii^s are best removed by the use of a mild gal- 
vanic current to destroy the papillte. Strong caustics should not 
be used, as too often the hair is not removed, though the skin may 
be permanently injured. Hair- and whisker-dyes should be avoided. 
Most of these contain ingredients injurious to the hair as well as 
to the general health. Cosmetics too ol'ten contain ingredients like 
lead, bismuth, mercury, etc., and their continual use is injurious 
to the texture, softness, and health of the skin. Oases are on 
record where the use of cosmetics has led to wrist -drt)p anil to 
general paralysis. 



36 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



Fig. 15. 



41. The Sebaceous or Oil Glands are always seated 
in the corium (Fig. 3). Their duct, as a rule, empties 
into the hair follicle. Each hair of the scalp is generally 
provided with two glands. The function of the fatty 
product is to oil the hairs, to keep the skin supple, and for 
protection. 

42. The oil gland is pear-shaped and lobulated. The lobules are 

made up of minute mem- 
branous sacs, lined with 
epithelium (156), The epi- 
thelium elaborates an oily 
fluid, which is always 
mixed with cells from the 
gland-walls. 

43. Dandruff is a scurf 
which forms on the head 
and comes off in small 
scales or particles. It con- 
sists of the dried products 
of the sebaceous glands 
•and cells from their walls 
and ducts (Fig. 15). Its 
most frequent cause is im- 
paired general health. 

44. The Sweat Glands are made up of tubes twisted 
in the form of a knot, leading to the surface by a long, 
sometimes spiral, duct (Fig. 10). These ducts terminate 
in openings on the surface of the skin, called ■pores. These 
glands are estimated to number upwards of 2,225,000. 
They give forth a clear, slightly saltish fluid. Their func- 
tion is to eliminate water from the system, to expel certain 




Fig. 15 {Leidy). Fragment of Dandruff from 
THE Head. — 1, Portion of dandruff, consisting of 
non-nucleated cells. 2, Several fragments, consist- 
ing of nucleated cells. 3, Isolated cells, some with 
and some without nuclei. 4, A cell more highly 
magnified, exhibiting granular contents and a 
nucleus. 



41. Where are the oil glands seated ? Relation to the hair ? Their 
function ? 

44. Describe a sweat gland. Number of these glands? Their 
function ? 



THE FRAMEWORK AND ITS COVERINGS. 37 

waste materials which collect in the blood, and, under the 
resulting evaporation upon the surface, to cool the body. 

45. The sweat glands are situated deep in the corium, or in the 
subcutaneous connective tissue. The knotted tubes are lined with 
columnar epithelial cells, which are the secreting agents. The 
tissues beneath the secreting membranes are very vascular. These 
glands are found, with few exceptions, in all parts of the body. It 
is still an open question whether the sweat, as a whole, is furnished 
by the glands alone, or whether a considerable part may not transude 
through the epidermis. The secreting activity of these glands is 
aided by vascular dilatation, and diminished by vascular contrac- 
tion (137). By the intimate relation of blood-supply and gland- 
activity, the temperature of the body is largely regulated (322). It 
is very probable that there are special nerves governing the activity 
of these glands. The amount of fluid passing away from the skin 
in twenty-four hours is considerable, varying from seven hundred 
to two thousand grains (one and one-half to four and two-fifths 
pounds). 

46. The Sweat or Perspiration which is evaporated 
as fast as it is thrown out on the skin is called insensible j^er- 
sjpiration, and that which accumulates on the skin, sensible 
perspiration. Most of the sweat passes off unknown to 
ourselves. The amount of sweat is greatly influenced by 
the temperature of the air, the clothing worn, the amount 
and kind of fluid taken, and the exercise indulged in. 
Other things remaining the same, an elevation of tem- 
perature favors, while a lowering of temperature retards, 
its secretion. 

47. To excite the perspiratory action of the skin, as in 
^the dry, hot skin of colds, the SorPSON INIethod is to be 

commended. Fill six or eight bottles with hot water (not 

46. Wliat is sensible perspiration ? Insensible perspiratioti ? Wbat 
IS said of the amount of perspiration? AVliat of the inlluenoe of 
temperature? 

47. Describe the Simpson sweating-bath. 

4 



38 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

much above 150°), and cork tightly. Wring six or eight 
woollen stockings out of hot water. Have them moist, not 
dripping wet. Draw one of the stockings over each bottle. 
Pack the encased bottles about the body and legs of the 
patient. Cover the patient well. After twenty to thirty 
minutes have elapsed, a thoroughly free perspiration will 
be eifected. Remove the bottles, wrap the patient in a 
warm blanket, and allow the action to continue half an 
hour. Remove the damp blanket, and place the patient in 
a warm, dry bed. 

FUNCTIONS OF THE SKIN. 

48. The skin is the protecting covering to the whole body. 
It is the main part of the body concerned in the sense of 
touch (467j. In the maintenance of the average tempera- 
ture necessary for the continuance of heakhy life (37° C. 
or 98.6° F.), the skin is the important heat-regulating 
organ. In twenty-four hours nearly seventy-eight per cent, 
of the heat lost by the body goes by the way of the skin. 
The thickness of the epidermis very much retards the re- 
spnatory function of this covering of the animal body, yet 
there is a small interchange of oxygen and carbonic acid 
gas. As a secretory organ, it gives forth the perspiration 
and the sebum. As an excretory organ, it may eliminate 
urea and other nitrogenous compounds (316), and thus 
lighten the work of the kidneys. As an absorbing surface, 
it can take in water to a very limited extent. If, how- 
ever, the epidermis be removed, fluids and even solids find^ 
their way into the lymphatic and blood currents quite 
rapidly. 

48. Give a function of the skin. "What is the temperature of the 
healthy body? How much body-heat is lost by the skin? The re- 
spiratory action ? Secretory and excretory actions ? 



THE FRAMEWORK AND ITS COVERINGS. 39 



HYGIENE OF THE SKIN. 

49. Clothing. — The object of clothing, from a physio- 
logical point of view, is to protect the body against cold 
and heat. In hot countries the wearing of any kind of 
clothing is inconvenient, yet the people know from expe- 
rience that the head must be shielded from the rays of the 
sun, and the abdomen protected against the hourly varying 
temperature, especially during the sleeping-hours ; but in 
cold countries the use of clothing is essential for comfort 
and the preservation of life. 

50. Clothing does not warm the body; it simply retards 
the radiation and conduction of the body-heat. Hence in 
cold climates the clothing should be designed to prevent 
the passing out of the heat from the body. In hot climates 
the clothing should be devised to protect against direct heat 
and to favor the escape of heat from the skin. In temper- 
ate climates the garments should be varied in form, mate- 
rial, and thickness in accordance with the changing seasons 
and temperatures. To .the Esquimaux, furs are essential ; 
to the laborer of the temperate regions, woollen ; to the 
people of the ^' Middle Kingdom,'^ cotton ; and to the 
tattooed Siamese coolie the cotton breech-cloth is more 
than enough. 

51. As to the use of clothes, Dr. Parkes sums up thus: 
^^ Protection against Cold. — For equal thickness, wool is 

much superior to either cotton or linen, and should be worn 

49. Object of clothing in hot countrios? In cold countries? 

50. The influence of clothini;-? The kind for coUl counliios? For 
hot countries? For temperate clinie?^? 

51. State the diflerent qualities of clotliini;' for protection against 
cold. Against direct heat. Against cold winds. Against oxcossivc 
perspiration. 



40 ANATOxMY, PHYSIOLOGY, AND HYGIENE. 

for all under-clothing. In case of extreme cold, besides 
wool, leather or water-proof clothing is useful. Cotton 
and linen are nearly equal. 

^^ Protection against Heat. — Texture has nothing to do 
with protection from the direct solar rays ; this depends 
entirely on color. White is the best color, then gray, yel- 
low, pink, blue, black. In hot countries, therefore, white 
or light-gray clothing should be chosen. 

^' In the shade the effect of color is not marked. The 
thickness and the conducting power of the material are 
the conditions (especially the former) which influence heat. 

^^ Protection against Cold Winds. — For equal thickness, 
leather and india-rubber take the first rank, wool the sec- 
ond, cotton and linen about equal. 

'^Absorption of Perspiration. — Wool has more than 
double the power of cotton and linen." 

52. The clothing should be loose-fitting. — In warm weather 
thin, loose, and porous garments favor the radiation of heat 
and the evaporation or removal of the abundant perspira- 
tion. Dry air, dry fur, dry, well-meshed wool, and silk are 
excellent non-conductors of heat. Not only are such mate- 
rials well adapted for cold climates, but where several 
thicknesses are worn the non-conducting layers of air favor 
the retention of body-heat. The astute Chinese gauge the 
weather by counting the number of cotton jackets they 
find it necessary to wear, as two-jacket weather, three-jacket 
weather, etc. By putting on our extra garments in a warm 
room some minutes before going out in the cold, we may 
secure a warm layer of air between our bodies and the 
over-garment. 



52. The clothing, how worn ? Kind of ? Name good non-conduc- 
tors of heat. Chinese gauge of the weather. Speak of over-garments. 



THE FRAMEWORK AND ITS COVERINGS. 41 

53. Water-proof clothing is an exceedingly hot dress, 
because it prevents the passage of currents of air and con- 
denses and retains the perspiration. Water-proof garments, 
boots, and overshoes should be worn only to keep out ex- 
ternal wet, and then only during the time of exposure. A 
person using india-rubber clothing experiences less injury 
from the effects of the retained perspiration if he wears 
woollen under-clothing rather than cotton or linen. The 
Council of Health of the French army have persistently 
refused to allow the introduction of water-proof garments 
into the army. 

54. Cold and damp feet cause much discomfort and not 
a little disease. If the boots " fit snug,'* perhaps "tight,'' 
then the blood-circulation is hindered and the conduction 
of heat facilitated. Wet leather is a good conductor of 
heat. If the boots fit tight and the leather be wet, then 
the heat of the feet will be removed faster than it is brought 
to or produced in them, causing cold feet, and inducing 
discomfort and, perhaps, disease. But when good skins 
are slowly tanned with ^' honest" bark, then " there is 
nothing like leather." Such leather does not readily ab- 
sorb moisture, and is a bad conductor of heat. If the boots 
" fit easy," then a layer of air is around and about the foot, 
promoting warmth and comfort. 

55. Night clothing should be thicker than that worn during 
the day. — 1. The night is colder than the day. 2. The 
radiation of heat from the body is much greater during 
the sleeping than the waking hours. A wool or hair mat- 

53. The effects of water-proof clothing. When injurious. 

54. Influence of snug'-fitting boots. Of wet leather. Of tlry 
leather. Of an easy-fitting boot. 

55. Why is more clothing required at night? Describe a healthy 
bed. Objections to feathers. The Italian idea. 



42 A^^ATOMY, PHYSIOLOGY, AXD HYGIENE 



tress, light, fleecy wool blankets, clean cotton sheets in or- 
dinary weather, or w^oollen sheets in severe winter weather, 
make a healtliy, sleep-inducing bed. Feathers above and 
feathers below make a very warm bed, but their influence 
is relaxing and enervating : besides, such beds do not admit 
of ready cleaning and airing. All bedding should be ex- 
posed to a current of air and to direct sunlight several 
hours each day. The Italian method of not making the 
bed until late in the day is to be commended, as it allows 
more time for the escape of the night's emanations. 

56. The clothing should be clean. — As portions of the 
excretions and secretions from the skin, dust and moisture 
from the air, and small particles from the house and work- 
shop adhere to or are absorbed by the clotliing, therefore 
the clothing should be frequently changed, often shaken, 
and well washed at near intervals. When taken from the 
body, all garments should be shaken, hung in a current of 
air, and at frequent intervals exposed to the direct sun- 
light. Under-garments should be changed every twelve 
hours, — that is, the night set should be aired and sunned 
during the day, and the day set aired during the night. 

57. Damp clothing is injurious. — All articles from the 
laundry should be well aired before being worn. When 
the clothing is wet by accident or exposure, it should be 
changed immediately, unless the person is exercising so 
vigorously as to prevent the slightest chilly sensation. 
When the exercise ceases, the body should be rubbed wnth 
a dry crash towel till a thorough reaction takes place. Beds 
and bedding that have not been used for some weeks be- 
come damp, and should be aired before use. 

56. What of the care of the clothing ? Of the under-clothing? 

57. Influence of damp clothing? Management of the body with 
wet clothins: ? Of the bed and beddins;? 



THE FRAMEWORK AND ITS COVERINGS. 43 

58. Clothing in childhood, in age, and in disease. — Per- 
sons in active employment need less clothing- than those 
engaged in sedentary pursuits ; the vigorous adult less than 
the child or the aged. The system of "hardening chil- 
dren/' by furnishing them with an insufficient supply of 
warm clothing, is inhuman, and, " as our clothing is merely 
an equivalent for a certain amount of food" (Liebig), it is 
certainly unprofitable. For the latter reason the gift of 
flannels and blankets to the aged and infirm at the opening 
of winter is most appropriate. Persons suffering from 
headache, neuralgia, dyspepsia, consumption, and other 
chronic maladies need more clothing than healthy persons 
under the same circumstances of life and occupation. 

59. The clothing should he suited to the climate, the occu- 
pation, and the time of day. — In the northern and central 
sections of the United States, merino (the weight and the 
amount of cotton admixture varying with the seasons) is 
undoubtedly the safest material for under-garments at all 
times. The change from thick to thinner garments should 
be made in the morning. The evening hour demands an 
increase of clothing, because of the coolness and dampness 
of the atmosphere and the less buoyant condition of the 
system. In certain sections of the country Boerhaave's 
maxim, " We should put off our winter clothing in mid- 
summer's day and put it on again the day after," should be 
put in })ractice. During the winter months the transition 
from the warm, every-day garments to the light "full 
dress," from active, exciting exercise in the hot, crowded 

58. The amount of clothing? The axiom of Liebiii;? Clothing- for 
the sick ? 

59. Adaptability of clothing for the sections of the ITnitod States? 
When should clothing be changed ? Boerhaave's maxim '.' Dangers 
of transition in clothing and temperature? 



44 

dancing-hall to the sudden pause, from the close, stifling 
room to the exposed corridor or balcony, and especially at 
any hour after midnight, is, to say the least, very hazardous. 

60. Light exercises a very salutary influence upon the 
skin. It is no less essential to the vigor of animal than 
of vegetable life. Dwelling-houses should be built with 
reference to the free admission of sunlight and air into all 
occupied rooms. The absence of light favors the accumu- 
lation of dirt and the growth of moulds. "Dirt, de- 
bauchery, and death" are successive links in the same 
chain. Ladies often suffer seriously from too much ex- 
clusion of sunlight. Except in very warm weather, all 
should practise exercising in the full sunshine. The health 
is often improved by sitting or reclining with the sun's 
rays falling on the back. 

61. BA.THING is indispensable to sound health, as well 
as to cleanliness. The skin soon becomes covered with a 
mixture of perspiration, oil, and dust, which, if allowed 
to remain, interferes with the action of the skin as an ex- 
cretory organ. This increases the action of lungs, kid- 
neys, liver, etc., which take upon themselves the excretory 
work which the skin fails to perform. By overwork they 
may become diseased. Again, obstruction of the pores 
prevents respiration through the skin, and deprives the 
blood of one source of its oxygen and one outlet of its 
carbonic acid (190). 

62. Bathing gives tone and vigor to the internal organs, — ^ 
When cool water (cool to the individual) is applied to the 

60. Action of light ? The arrangement of rooms ? Influence of 
dark, damp rooms? Of direct sunlight? 

61. The need for cleansing the skin ? 

62. The influence of cool water in bathing? What is reaction? 
Effect of reaction ? What of the smooth muscles ? 



THE FRAMEWORK AND ITS COVERINGS. 45 

body, the skin instantly shrinks. This contraction dimin- 
ishes the capacity of the cutaneous blood-vessels, and a 
portion of the blood is thrown upon the internal organs. 
The nervous centres are stimulated, and new impulses are 
sent to the whole system. This causes a more energetic 
action of the heart, and a consequent rush of blood back 
to the skin. This is the state termed reaction^ and is the 
first object and purpose of every form of bathing. By 
this reaction the internal organs are relieved, respiration is 
lightened, the heart is made to beat more calmly and freely, 
the tone of the muscular system is increased, the appetite is 
sharpened, the mind is made more clear and strong, and the 
whole system seems to possess new power. Cold sponging 
and cold bathing are the gymnastics of the smooth muscles 
to a person of robust health. Regularity in bathing is 
necessary to produce permanently good effects. 

63. The simplest modes of bathing are by means of the 
sponge or the shallow bath. The body may be quickly 
sponged over, wiped dry, and subjected to friction. The 
water may be warm or cold. If cold, the bath should be 
taken in the early part of the day and followed by exer- 
cise. The warm bath should usually be taken just before 
retiring. If taken at other hours, it should be followed by 
rest from half an hour to one hour under proper covering, 
followed by exercise. 

64. The shallow bath, in lohich the body is partly immersed 
in water, is very pleasant and safe, provided the bather ex- 
ercises in it by vigorous rubbing and does not remain too 
long. For a cold bath, it is not often safe to exceed five 



63. Speak of the spong-e Imtb. Of the cold buth. Of the warm 
bath. Precautions. 

C4. Duration of bath. Temperature of bath. Of frietion. 



46 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

minutes, and with delicate persons the time should rarely 
exceed two or three minutes. A bath is considered cold 
when below 75° ; temperate, from 75° to 85° ; tepid, from 
85° to 95°. This and every other form of bath should be 
followed by thorough friction with a coarse towel or flesh- 
brush. 

65. The hour for ablution is of imjportance. It should 
neither immediately precede nor immediately follow a meal. 
The same is true of severe mental and muscular exercise. 
The bath is less beneficial in the afternoon than in the 
forenoon. The best time for sea-baths is two or three hours 
after breakfast. The system is then at '^ flood-tide,'^ while 
from that time till the retiring-hour the tide is ebbing : 
hence the worst time for a cold bath is at bedtime. Then 
friction with the flesh-brush can be substituted. For those 
who cannot choose their time, the hour of rising will answer 
very well, — that is, for many persons, especially if they 
become accustomed to the use of water by beginning at 
another and a better hour. If the mind and body are 
brightened by the early bath, and an exhilaration follows, 
the bath is beneficial ; if, on the contrary, languor follows, 
and the skin looks blue or too pale, it is injurious. That 
the bath is to be followed by exercise must not be forgotten. 

QQ. In diseases of the skin, and in many clwonio ailments 
of the internal organs, bathing is a remedial measure of great 
'power. In disease which has baffled the skill of physicians, 
depending wholly upon internal remedies, the eflect of a 
systematic course of baths is often surprising. Like other 
curative means, the baths should be directed by those Avho 

65. The bathing-hour. The flood-tide of the system. Symptoms 
following a beneficial bath. Following an injurious bath. 

66. Bathing in disease of the skin, and in other diseases. Give the 
simple rules. 



THE FRAMEWORK AND ITS COVERINGS. 47 

thoroughly understand the use of water as a remedial 
agency. 

A few simple rules must be observed in bathing. The 
face and head should be wet in cold water before the bath. 
Cool baths should not be taken when the person is chilly, 
perspiring, or greatly fatigued. All general baths should 
be taken briskly, and the skin well rubbed and quickly 
dried, inducing a healthy glow over the whole body. Exer- 
cise should follow most baths. 

67. Soap is admirably adapted to the removal of dirt 
from the skin ; but if it is too freely used on the general 
surface of the body it dissolves the oily secretion of the 
sebaceous glands, leaving the skin dry and harsh. The 
external epithelial cells may be removed too rapidly when 
soap is used in excess, leaving the skin without its proper 
protection. The best kinds of soap should always be 
employed. 

67a. Ethyl-alcohol (241) in excess of the amount which the 
organism can oxidize (305a), circulating in the blood, works mis- 
chief in the skin as well as in other soft tissues (87a). Its con- 
tinuous use induces an intense congestion of the blood-tubes of 
the skin, which is followed by an excessive activity of the areolar 
and secreting tissues. The outcome of this abnormal activity is an 
alteration in the structure of the skin and a modification of the 
activities of the glands of the skin. Alcoholics alone, when long 
continued, are capable of inducing skin disease, as the " brandy- 
nose." Alcohol almost always aggrav^ates a skin trouble and, fur- 
thermore, tends to keep up an existing cutaneous disease (eczema, 
acne, etc.). To some forms of skin disease (specific) it always 
imparts a serious character. 

67. What of the use of soap ? 



CHAPTER lY. 

THE CONTKACTILE AND IRRITABLE TISSUES. 

68. The nerve and muscular tissues are irritable, — that is, when 
they are stimulated, a certain amount of energy, latent in their 
protoplasm, is set free as heat, motion, impulse, etc. Muscle alone 
is contractile, — that is, under the influence of a stimulus it is capable 
in itself of causing changes in its own form. The contractile tis- 
sues embrace the striped muscle, the unstriped muscle, the cardiac 
muscle fibre, and the ciliated cells. 

69. AVhen a piece of an india-rubber band is pulled out by the 
exercise of force, the particles of the rubber tend to resume their 
former position. When a piece of muscle is so stretched, the same 
tendency is noticed, but in a less degree. If now one end of the 
band or the muscle be set free, then the stretched elements resume 
at once their former quiescent position. This shows the property 
of elasticity. 

70. When a bit of fresh muscle, slightly weighted, is stimulated, 
as by heat, or acid, or electricity, then the muscle shows changes in 
form, in length, and a wave-like line of progression, and the weight 
is moved. As often as the muscle is stimulated up to the point of 
exhaustion, these changes will be noticed. These movements re- 
sult from the setting free of energy latent in the muscular tissue, 
and not from an external force. This property of the fibre is called 
contractility. If a rubber band 'be similarly stimulated, no con- 
tractions follow. 

71. The Striped Muscular fibre (Figs. 16, 17) consists of fine 
long filaments, which break up into smaller fibrillae. Fine, alter- 
nate dim and bright cross-bands are seen passing through the whole 
thickness of the fibre. The cross-marks are called strife. The 
fibrillae are seen to be made up of fine disk-like bodies, called sar- 
cotic elements. The fibres are surrounded by a delicate, transparent 
sheath of tissue, called sarcolemma. This kind of fibre contracts 
with rapidity. Because the shortening and lengthening are seen 

48 



THE CONTRACTILE AND IRRITABLE TISSUES. 



49 



to be under the control of the will it is called voluntdTry muscular 
fibre. The great muscles of the body are made up of this kind of 
fibre (512). 



Fig. 16. 



Fig. 17. 





II II, . 

Fig. 16 (Leif??/). Fibrils from a Muscular Fibrf of ihe Axolotl, a B\tkachian 
Reptile; highly magnified, a, Bundle uf fibrils. />, An isolated fibril. 

Fig. 17 {LeUlij). Two Portions of a Muscular Fasciculus, from the trapezius mus- 
cle ; highly magnified. 1, Two portions of a muscular fasciculus, composed of prismatic 
striated fibres terminating below, in rounded extremities, among the fibrous tissue of the 
commencing tendon. 2, Cut extremities of the fibres, showing their prismatic form. 
3, Delicate sheath, composed of obliquely-crossing filaments of areolar tissue. 4, The 
fibres of the commencing tendon. Partly a diagram. 

72. The Unstriped Muscular fibre appears as long, pointed- 
at-both-end cells, containing granules and nuclei. The fibres arc 
flat, and are arranged in the form of bundles. No cross-markings 
are to be seen. This kind of fibre contracts slowly. The contrac- 
tion and relaxation are independent of the will : hence it is called 
involuntary muscular fibre. Such muscular bands are found in the 
intestines, the ducts of glands, and the larger blood-tubes. 

73. The Cardiac Muscular fibres show the cross-stri:v which 
are seen in the voluntary muscle, but they are arranged in h)ng 
bands. These fibres frequently anastomose, and often have branches. 
There is no sarcolemma. Nuclei are to be seen at quite regular 

c d 6 ' 



50 



AND HYGIENE. 



Fig. 18. 




DlA- 

Colum- 



spaces. This form of contractile tissue is found in the muscle of 
the heart. 

74. Ciliated Cells. — Upon certain surfaces of the body are 
found cells which are famished with very actively vibrating hair- 
like processes, or cilia. The cilia bend their ends 
in a given direction, but recover slowly. They 
work together, and, as a result, the fluids resting 
upon their surfaces move in definite currents. 
These motions continue after the cells are removed 
from the body. The ciliary motion is probably due 
to changes going on in the protoplasm of the cell- 
body. The cilia found in the air-passages assist 
in the respiratory changes, causing movements in 
the smaller air-passages of the lungs (164, 183). 

75. Physiology of Muscle. — If muscular 
fibres be stimulated, as by heat, acid, pinching, or 
nervous impulse, contractions are to be seen. If 
the stimuli be removed, the fibres resume their 
earlier form and position. After the contact of the 
stimulus there is a brief rest, after which the fibre 
shortens slowly, then more rapidly, later more 
slowly, followed by relaxation and the taking of the earlier position. 
If the stimulus is repeated rapidly, the fibre may remain in a con- 
stant state of contraction, or tetanits. In the living muscles, con- 
tractions are usually excited by nervous impulses. The muscle also 
exhibits electric currents. The movements are due to the contractile 
energy inherent in the muscular elements, not to an external agent. 

76. Muscular contraction produces an elevation of the tempera- 
ture, and if the contractions occur in rapid succession sounds may 
be heard. During the action, acid is set free. Eepeated contrac- 
tions exhaust the muscle-energy, and the point is readily reached 
at which the fibre refuses to contract under the given stimulus ; but 
if a stronger or a new kind of stimulus be used, the muscle again 
responds. Rest alone restores the contractile power. Rest and 
proper muscle-food, how^ever, restore the power sooner. The short- 
ening of the muscle may be as much as three-fifths of its length. 
The exact function of the striae has not been determined. 

77. The eminently contractile muscular fibres and cilia-cells, and 
the eminently irritable tissues, nerve-cells, and nerve-fibres of the 



Fig. 18 

GRAM.— 1, 

nar ciliated epithe- 
lial cells. 2, Cilia. 
3, Nuclei. 4,Young 
cells. 5, Basement 
membrane. 6, Fi- 
brous layer. 



THE CONTRACTILE AND IRRITABLE TISSUES. 



51 




Fig. 19. Nerve-Filaments 
sheath. 



decussating, with their 



body, are the most important tissues. The nerve and muscular 
tissues of the body are the master-tissues. The relations between 
them are so intimate that it is desirable to consider their action and 
their relations in the same section. 

78. The white or tubular nerve-fibres consist of an outer, 
thin, transparent, limiting layer of connective tissue (22), enclosing 
a layer of transparent fluid 

fat. This latter is the wAi^e Fig. 19. 

substance of Schtoann. 

Within this is a darker, 

firmer, denser, albuminoid 

core, called the central 

band axis. This latter, 

like the copper core of the 

submarine cable, is the 

important part of the fibre. 

This kind of fibre composes the white parts of the brain and spinal 

cord (345), and the chief substance of the nerves. 

79. The GRAY or Remak's NERVE-fibres are pale, soft, granular, 
and somewhat flat in appearance. They have no distinct invest- 
ing structures. They contain many dark nuclei. These fibres are 
abundant in the nerves of the sympathetic system (386). 

80. The NERVE or ganglion cells consist of finely-granular 
cell-bodies, sometimes colorless, sometimes pigmented, which con- 
tain large, round, vesicular nuclei, and are limited by a thin mem- 
brane. In the isolated ganglia other investing membranes are to 
be made out. Many of these cells exhibit one or more tail-like pro- 
longations (unipolar, bipolar, multipolar cells), while others have 
none. Nerve-cells are found in the brain, spinal cord, and other 
ganglia. 

81. Physiology of the nerve-cells and fibres.— A simi)le 
ideal nerve system may be conceived to be composed of— 1, a sen- 
sitive nerve-cell or receiving-cell on the surface of the body ; 2, an 
afferent or sensory nerve-fibre (inward transmitting line) ; 3, a cen- 
tral nerve-cell in the interior; 4, an efferent or motor nerve (outward 
transmitting line), ending in, 5, a muscular fibre cell. The fibres of 
nerves act like the conductors in the electric cable; the receiving- 
cells, like the telephonic transmitter; but the central cells perform 
a duty not yet delegated to clever mechanisms and physical forces, 



52 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

— that of receiving impulses and then of originating and sending 
out differing impulses. 

82. Eeflex action. — If the receiving surface of a system similar 
in principle but more complex in structure than the ideal system 
(81) should be excited, as by the prick of the skin, an impulse passes 
over the afferent fibres inward. This impulse, reaching the central 
cells, induces changes in the protoi^lasm of the same,^ — ^that is, the 
impulse is recognized, acted upon, and perhaps registered, in the 
cell-structure. The changes in the protoplasm induce the sending 
of a different impulse over the efferent fibres, which impulse, acting 



Fig. 20. 



Fto 21. 







13^ 






cr- 



U- 



Fig. 20 {Kolliker and Hannover). 1, Nucleated cells from a sympathetic ganglion. 
2, Branched or stellate cells from the graj' substance of the spinal cord. 3, Branched 
cells from the medulla oblongata. 4, Simple and branched cells from the convolutions 
of the brain. 5, A large cell from the gray substance of the brain. Magnified one hun- 
dred diameters. 

Fig. 21 (Leidy). Portion of Gray Substance, from the Exterior of the Cere- 
bellum. — 1, Two nerve-cells with bipolar prolongations. 2, Granular matter. 3, Nuclear 
bodies. 4, Nerve-fibres. 



on the proper receiving apparatus, as the cells of a series of muscles, 
gives rise to motions. This, in outline, is an explanation of the 
complicated phenomena of reflex action. The brain and spinal cord 
are the chief seats of reflex action. The majority of these phe- 
nomena are very complicated, as in the muscular movements made 
by a sleeping person to remove a fly from a part of the face, or the 
series of coughs, varying in intensity and rapidity, employed to 
remove dust from the air-passages. 

83. Experiments show that the impulses from the receiving sur- 
face towards the interior, and from the central cells outward, are 
transmitted equally well ; that only a small amount of energy is 



THE CONTJRACTILE AND IRRITABLE TISSUES. 53 

expended in the transit ; that the rate of motion is much slower 
than electricity; and that varying conditions of the nerve-fibres and 
of the system in general retard or accelerate the rate. No chemical 
or physical changes in the fibres resulting from the passage of im- 
pulses have been detected. Natural electric currents pass over the 
fibres. The changes in the central cells are probably accompanied 
by the expenditure of much energy, being manifest to us by waste 
of tissue and weariness. Also, it is probably true that the peculiar 
make-up of the nerve-cells, their repeated duties, and their condi- 
tion of ease or disease, exercise an influence on the quality, quan- 
tity, and degree of force of the new impulse generated therein. 

84. Automatism. — A series of nerve-cells grouped together con- 
stitute a nerve-centre or ganglion. Distinct centres have been local- 
ized in parts of the spinal cord, the brain, the muscles of the heart, 
and the intestinal muscles. TKe protoplasm of nerve-centres appears 
to possess the power of originating vital impulses. This power of 
developing an impelling vital force is called automatism. The im- 
pulses so arising, when transmitted outward, may be made known 
to us as muscular movements, in volition, in speech. The pecu- 
liar, w^orm-like, progressive action of the muscular fibres of the 
intestines (265), and the motions of the heart (94), are the best 
examples of automatic action. 

85. Inhibition. — When nerve-cells or groups of cells are al- 
ready in action, as of the heart-ganglia, causing the contractions 
of the muscles of the heart, a- new impulse may arise, and so act 
upon the cells or their activities as to modify the impulses. This 
new impulse may increase, or it may decrease, the former action ; 
in the heart, it may diminish the number of beats, may change the 
force of each contraction, or it may have the opposite effect. The 
retarding of the influence of a group of cells is called inhibition. 
This is well shown in the control of certain centres in the brain 
over the action of the heart (128). 

86. Muscle and Nerve. — Late investigations show that, in the 
striped nuiscle, the nerve-fibres penetrate the sarcolomma and end 
beneath it in a fine, granular, plate-like, nucleated substance, in 
close contact with the contractile elements. The method of ending 
in the unstriated muscle is not yet settled, though the nerves end 
in many fine meshes in certain cases, and by fine terminal fibres in 
the contractile fibre cells in othei-s. 

6* 



54 

87. To account for the contraction of a living muscle, a theory- 
lias been advanced, that — 1, an impulse arises in a nerve- cell ; 2, a 
nervous impulse is transmitted along the nerve to the muscle ; 3, 
the nervous impulse is changed into a muscle impulse ; 4, the send- 
ing of this new form of impulse along the muscular fibre gives rise 
to the contraction. The change in the form of the muscular fibres 
is accompanied by chemical changes, the exact nature of which is 
hot yet known. This much is known, that carbonic acid and lactic 
acid become more abundant. The source of muscular energy is the 
chemical decomposition of chemical substances in the muscle. The 
immediate muscle food-material, stored up partly, at least, in the 
muscle, is mainly non-nitrogenous and carbo-hydrates. During 
muscular contraction there is an increased consumption of oxygen 
(181, 182), and an increased elimination of carbonic and lactic 
acids : the fact that the latter compounds are relatively larger than 
the oxygen received at that time, will account for the needed rest 
(529). The nitrogen-elimination is but slightly increased during 
exertion. During the contraction, heat and muscular energy are 
made manifest. 

87a. Alcoholics habitually taken in excess of the power of the 
system to oxidize (305a), circulating in the blood, induce fatty — 
or hardening — degenerative changes in all the soft tissues (243). 
Alcohol has a special affinity for nerve tissue. After the taking of 
a large dose, or during the constant circulation of alcohol in the 
blood, it enters the brain, spinal cord, and ganglia in larger pro- 
portional amounts than other tissues. Under continued action 
of the alcoholized blood the 7ierve cells and central band axes (78, 
80) become more or less fatty and shrunken, and the delicate 
webs of areolar fibres of the centres, at first increasing in size, 
later contract, reducing the bulk of the centres, and hinder or stop 
the normal activity of nerve cells. Hence coordinate muscular 
action (372, 393, 494, 515), as well as mental action (4t)8), is ob- 
structed, perverted, or stopped. Alcoholics continuously circulating 
in the blood seriously affect the nutrition of the muscular tissues 
(147a). They lessen the regulative action of the vaso-motor centres 
(137) over the skin capillaries, and thus cause great heat loss (322). 
The heat evolved from oxidation of alcohol is far less than the 
heat loss due to its nerve-centre paralyzing action (245). 



CHAPTER y. 

THE VASCULAR SYSTEM AND THE CIECULATION. 

88. Three great cavities are formed in the framework 
of the body: the skull (Fig. 38), the chest or thorax 



Fig. 22, Section of a Small Mammal.— 1, Trachea. 2, Lungs. 3, Heart. 4, Dia- 
phragm. 5, Liver, 6, Stomach. 7, (Esophagus. 8, Kidney. 9, 9, Intestines, 10, 
Bladder, 11, Cerebrum. 12, Cerebellum. 13, J3, Medulla spinalis. 14, 14, Vertebra\ 

(Fig. 23), and the abdomen (Fig. 23). Tliere is a longi- 
tudinal cavity in the spinal column (Fig. 75) continuous 
with that of the skull. 

Dissection.— Place a rabbit, dog, or rat on its back. Make an incision in the middle 
line of the body from the lower jaw-bone to the pubes. Dissect up the skin as fur Iniok 
as possible on each side, and \nn or tie it back with threads. The ribbed part oxpi>sod 
is the thorax, and the soft part the abdomen. Observe the external inusclos of the front 
thorax, the pectoralis and the seiralm, the former being the thicker and attached to the 



88, Name the throe grout cavities of the body. What of the spinal 
column ? 

65 



56 AX ATOMY, PHYSIOLOGY, AXD HYGIENE. 

flat central bone, the sternum, and to the arm-bone, the humerus, and the latter having 
numerous saw-like digitations for insertion. The ribs are seen to be connected with the 
sternum by means of a white, gristle-lilie material, the costal cartilages. Cut through, 
on each side of the sternum, the -nhite cartilages, making the cut as near the blue hard 
rib as possible. At the inferior end of the sternum raise the bone and cut away the mus- 
cle, the diaphragm, which holds it in place. The freed end is now to be raised, freed 
from its under parts with a few nicks of the knife, turned over towards the chin, and 
the ligamentous attachments of the sternum to the right and left upper ribs severed. 

Dissect the skin and subcutaneous tissues from the neck parts. On the front neck, to 
the right and left, we see a thin tube holding dark blood, the jugular vein. In the 
middle line cut throiigh the thin muscle, plaUjsrnu, and draw it to the right and left. 
Remove the layers of tissue beneath until you expose the Avhite, ring-like tube, the 
trachea, and the cartilaginous enlargement above, the larynx. Just above the larynx can 
be felt a Y-shaped bone (the hyoid hone), and below the larj-nx, a fleshy mass on each side 
of the trachea, the thyroid body. By drawing the muscles and connective tissue from 
the trachea, there will be brought into view, i-unning nearly parallel to it, a firm, whip- 
cord-like tube, the carotid artery ; near it, thinner tubes, containing dark fluid, the veins, 
and a white, string-like fibre, the pneiunogastric nerve. If the larynx is followed upward, 
it is found to end in a muscnlo-membranous cavity, the pharynx. Beneath and to one 
side of the trachea is to be seen a collapsed tube with thick fibrous walls, the ocso2jhagus, 
which is seen to open into the pharynx above. 

Now cut the larynx free from the pharynx, then raise and separate the parts from the 
oesophagus and the muscles of the neck below, and pull towards the thorax. The trachea 
will easily be removed from contact with the oesophagus. Put two strings around each 
jugular vein, about an inch apart ; tie them so as to compress the tubes, and sever the 
veins between the ligatures. Sever the carotids ; but, as they are empty, ligatures are 
not needed. Now observe the contents of the thorax, — two lateral compartments, formed 
by the thin, smooth-surfaced jj/ejo-a, lining the chest-walls, each compartment containing 
a shrunken, pinkish-white, spongy organ, the lungs, of which the right is the larger. Tie 
a tube in the trachea, and fill the lungs with air, by blowing into the tube. Notice the 
deep lines dividing the lungs into lobes, and the irregular lines marking lobules, situated 
just under the pleura. Between the lungs is a sac, the pericardium, containing fluid and 
a flrm, pear-like, fleshy organ. Projecting and arching into the thorax from the abdo- 
men is seen a muscular and fascia-like partition, the diaphragm. The pericardium is 
attached to this, and should be cut free ; but the lungs are not attached to the diaphragm. 

Open the pericardium with the scissors. It is seen to contain a small amount of fluid, 
and to be lined by a smooth, close, serous membrane. Floating in this pericardial fluid 
is a flrm, pear-shaped, muscular organ, the heart. Its apex, or free point, is turned 
towards the ribs, and its broad, tube-attached base towards the back. 

Now continue the separation and elevation of the trachea, arteries, and veins, in a 
mass, down into the thorax. After the large tube, the aorta, is cut below its arch, the 
lungs and the heart can easily be raised out. The trachea is seen to divide into two tubes, 
the bronchi, which in turn divide and subdivide as they enter the lungs. From the heart 
are seen tub^s, arteries and veins, running into the lungs in company with the bronchia. 
Rising from the base of the heart is seen a large, round, gapiug tube, the aorta, which 
arches, gives off several branches, among them the carotids, and passes downward along 
the backbone of the animal, where it is called the thoracic aorta. This latter gives off 
many branches to the right and left, and passes out of the thorax through a hole in the 
diaphragm. If the lungs and trachea are now separated from the heart and vessels, and 
thrown into water, the lungs will be seen to float and the heart or the tubes to sink. If 
a bit of the lungs be held under water and then squeezed, small bubbles of air will rise 



PAROTID GLANO - ^tcno oucr- 



BXTBRNAL JUGULAR MEIN 

WTEBmL JUGULAR VEIIV 

CLMICLC 




Fig. 23. 

The Vasculak ArrAu.vns am> tmk ("iiu'vi.atiov. 



58 * ANATOMY, PHYSIOLOGY, AND HYGIENE. 

to the surface. If a bit of the lungs be pinched, a peculiar sensation, called crepitation, 
will be noticed. It is thus shown that the collapsed lung still holds a certain amount 
of air in its smaller tubes and cavities. 

There will now remain in the thorax the parietal pleura, the pericardium, the oesopha- 
gus, the thoracic aorta, and the thoracic duct, which latter may be found, after careful dis- 
section, in the left side of the chest, near the backbone. The oesophagus, the thoracic 
duct, and a large tube with thin walls, the ascending vena cava, are seen to enter the abdo- 
men through perforations in the arching diaphragm. 

Microscopic "Work. — Cut cubes of the organs as before, and place in alcohol No. 1 for 
hardening. Examine a bit of the muscle of the heart after careful teasing. Compare 
with intercostal muscle. Make thin sections of the aortic walls, of the valve-tissues, etc. 
Examine heart and vein. Prick your finger. As soon as possible, transfer a drop to a 
clean slide. Breathe on the lower side of the cover-glass, and cover at once. Spread the 
drop so thin that little color is visible. At first use a 1-inch objective ; then a J^-inch. 
Study the red corpuscles. (1 .) They tend to take the shape of rouleaux. (2.) Focus down ; 
they appear clear on the outside and dim in the centre, then clear in the centre and dim 
outside, — i.e., they are biconcave. (3.) In profile they are dumb-bell shape. (4.) Near 
the edge of the glass they appear crenate, owing to evaporation. Their size is about 
aaVrj of an inch. Find a inhite corptiscle. It is somewhat adhesive, has an irregular form, 
is colorless and granular, has a transparent nucleus. To a fresh drop add dilute acetic 
acid; the red corpuscles swell up, but show no nucleus; the ivhite show granules and an 
irregular nucleus. Add a drop of five per cent, sodium chloride solution, the red become 
shrivelled and crenate. Note between the rouleaux minute interlaced filaments of fibrin. 

89. The Thorax (148) is a framework of bones and car- 
tilage filled in with soft tissues. It is conical in shape, the 
base being towards the abdomen. Its capacity during life 
is continually undergoing changes. It contains and pro- 
tects the central organs of circulation and respiration. 

Dissection of the Heart. — Procure the heart of a sheep, ox, or dog. The front of 
the heart may be recognized by a groove filled Avith fat. Hold the heart with the front 
towards you. The right ventricle in your left hand is more yielding, because its walls are 
thinner, than the left ventricle in your right hand. Observe the gaping puhnonai-y artery 
rising near the middle line, and back of it the large, elastic, tubular aorta. Tie a tube in 
the pulmonary artery and fill it with water. The fluid does not enter the heart, it 
being stopped by the semilunar valves. Test the aorta in the same manner. If the valves 
are uninjured, the water will not pass into the heart. 

Lay open the ascending and descending vense cavse. Allow the cuts to meet in front of the 
right auricle. Note the size of the venae cavse, the thinness of the walls, and the absence 
of valves between them and the auricle. Observe the size, form, and thickness of the 
walls of the auricle and its dog-ear appendage. Cut away most of the right auricle. Hold- 
ing the ventricles in the left hand, pour some water suddenly througli the opening into 
the ventricle. The tricuspid valves will float up and close the opening. Allow the water 
to pass out through the semilunar valves. Introduce the scissors between two of the 
folds of the tricuspid valve, and cut a slit through the ventricular wall to the apex, then 

89. What is the thorax ? Shape ? Capacity ? Contents ? 



THE VASCULAR SYSTEM AND THE CIRCULATION. 59 

turn the scissors and cut alongside of the septum towards the pulmonary artery. Observe 
on the ventricular side of the tricuspid valves the many thin fibres attached to the folds 
of the valves, the chordse tenditiese, and their attachment at the other end to the columnse 
carnese, or muscular pillars. 

Hold the heart-ventricle. Pour water into the pulmonary artery. Raise the ventricular 
flap, and observe from below the form and mode of closing of the semilunar valves. Then 
continue the last incision, and lay open the semilunar valve and the pulmonary artery. 
Notice the little nodules in the free edge of each flap, the corpora Arantii, and the little 
pouches in the arterial walls opposite each flap, the sinuses of Valsalva. 

Lay open the left auricle in the same manner as the right. Study the mitral valve, and 
use water as before. Note the thickness of the walls of the pulmonary veins and of the 
auricles. Lay open the left ventricle in the same manner as the right. Note the very thick 
walls and the great firmness of the tissues near the apex. Compare the walls of the 
auricles and ventricles as to thickness and firmness. Observe the mitral valve from the 
ventricle. Notice its greater thickness and rigidity as compared with the tricuspid, also 
the increased size and strength of the chordae tendineae and the columnse carnese. Lay 
open the aorta. Examine its coats, their layers, thickness, and elasticity. Study the 
semilunar valve, the corpora Arantii, and the sinuses of Valsalva, and note their entrance 
to the coronary. Observe the entrance to the coronary arteries (the nutrient arteries of 
the heart-muscle) in the anterior sinuses. 



THE HEART. 

90. The heart is the great central pump of the vascular 
system. In the adult man it is about the size of the closed 
fist. Its base is connected with the large blood-vessels, and 
is directed upward and backward. Its apex is free, and 
points downward and forward to the left of the sternum. 
It is a hollow muscular organ. It is divided by a longi- 
tudinal septum into two chambers, the right and the left 
heart. After birth these two chambers do not communicate. 
Each chamber is divided into two cavities, the auricle and 
the ventricle. The auricle and ventricle of the same side 
communicate. 

91. The Auricles are placed at the base of the heart. 
Their walls are thin. They receive blood from the veins 
and propel it into the ventricles. The Ventricles are 



90. What is the heart? Size? Shape? Apex? Chambers? 
Cavities ? 

91. What of the auricles ? Of the ventricles ? That of the right ? 
That of the left ? 



60 

situated below the auricles. Their walls are quite thick, 
that of the left being about three times thicker than that 
of the right. From each ventricle extends a tube called 
an artery, that of the right leading to the tubes of the 
lungs, and that of the left to all parts of the body by 
many branches. 

Fig. 25. 





Fig. 24. A Front View of the Heart.—!, The right auricle of the heart. 2, The 
left auricle. ?>, The right ventricle. 4, The left ventricle. 5, 6, 7, 8, 9, 10, Vessels 
through which the blood passes to and from the heart. 

Fig. 25. A Back Yiew of the Heart.— 1, The right auricle. 2, The left auricle. 3, 
The right ventricle. 4, The left ventricle. 5, 6, 7, The vessels that carry the Wood to 
and from the heart. 9, 10, 11, The vessels of the heart. 

92. To direct the currents of blood in the proper course, 
valves are placed in the heart. Between the right auricle 
and ventricle is a valve, composed of three pointed, mem- 
branous curtains, the tricuspid valve. The valve opens 
towards the ventricle. Between the ventricle and the 
artery leading to the lungs is a valve, composed of three 
semicircular, membranous folds, named semilunar valve. 
This valve prevents the blood from returning to the right 
heart. 



92. Object of the valves. Describe the tricuspid. The semilunar. 



THE VASCULAR SYSTEM AND THE CIRCULATION. 61 



Fig. 26. 



93. Between the left auricle and ventricle is a valve, 
formed of two segments or curtains, named mitral valve. 
These curtains and their ad- 
juncts are stronger and thicker 
than those of the right side. 
The opening from the ventri- 
cle to the aorta is provided 
with a semilunar valve which 
is thicker and stronger than 
that of the right side. This 
valve prevents the return of 
the expelled blood from the 
aorta to the ventricle. 

94. Heart Motive Pow- 
er. — The heart propels the 
blood from the interior of its 
ventricles into the tubes lead- 
ing to all parts of the lungs 
and the system, by means of 
successive regular contractions 
of its ventricular walls. The 
immediate source of the motive 
power is the contractility of its 
muscular tissue. The muscular 
contractions are caused by im- 
pulses which arise in the heart 
itself. The impulses arise in 

and are due to changes in the nerve-ganglia scattered in 
the heart-substance (84). 

95. The chambers of the heart are lined with a very fine, 




Fig. 26. Diagram of the Heart 
AND Great Blood-Vessels. — 1, Superior 
vena cava. 2, Inferior vena cava. 3, 
Tlie right auricle laid open. 4, The 
riglit ventricle laid open, showing seg- 
ment of tricuspid valve, chorda; ten- 
dinese, and papillary muscle. 5, Pul- 
monary artery. *, Two semilunar 
valves. 7, Part of left auricle. 8, Left 
ventricle. 0, Aorta, with the branches 
from the arch. 9', The thoracic aorta. 
The arrows show the coui-so of the 
blood in the veins. 



93. What of the mitral valve? Of the aortic semilunar valve? 

94. Tlio function of the heart? Source of the motive power? 

a 



62 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



smooth membrane, called endocardium. This membrane is 
continuous with the lining membrane of the large blood- 
tubes. The heart is suspended in the folds of a serous sac, 
called the pericardium (156). The ser^um between the heart- 
layer and the outer layer (mediastinal) permits of great 
ease of movements. 



Fig. 27. 



Fig. 28. 



4-'.. 





Fig. 27. Diagram of the Heart, with its Investments. — 1, 1, Eight and left auricles. 
2, 2, Right and left ventricles. 3, i. Pericardium. 5, Pulmonary artery. 6, Aorta. 

Fig. 28. Diagram of the Heart and Yalvf.s. — 1, Descending vena cava (vein). 2, 
Ascending vena cava (vein). .3, Right auricle. 4, Opening between the right auricle 
and the right ventricle 5, Right ventricle. 6, Tricuspid valves. 7, Pulmonary artery. 
8, 8, Branches of the pulmonary artery that pass to the right and left lung. 9, Semi- 
lunar valves of the pulmonary artery. 10, Septum between the two ventricles of the 
heart. 11, 11, Pulmonary veins. 12, Left auricle. 13, Opening between the left auricle 
and ventricle. 14, Left ventricle. 15, Mitral valves. 16, 16, Aorta. 17, Semilunar 
valves of the aorta. 

96. Heart-Steucture. — The walls of tlie right auricle average 
two twenty-fourths of an inch in thickness ; the left, three twenty- 
fourths; the right ventricle, three twenty-fourths, and the left, nine 
twenty-fourths. The left increases in thickness as life advances. 
The heart muscle-fibre (73) is striated, often branched, and often 
joined to adjacent fibres. The fasciculi of these fibres interlace, 



95. "What of the endocardium ? Of the pericardium ? 



THE VASCULAR SYSTEM AND THE CIRCULATION. 63 

and the sarcolemma is, as a rule, absent. There is scarcely any 
areolar tissue between the fibres, and hence the peculiar firmness of 
the contracted heart. The arrangement of the bands of muscular 
fibres is very complicated. 

97. To the margins and ventricular surfaces of the tricuspid and 
mitral valves are attached numerous fine, inelastic cords, the chordcB 
tendinece, the other ends of which are attached to the papillary mus- 
cles projecting from the heart-wall in the interior, or directly to the 
ventricular walls. Their combined functions are to prevent the cur- 
tains of the valves from being crowded into the auricular cavities 
during severe contractions. In the middle of the free edge of each 
fold of the semilunar valve are little nodules of fibro-cartilage. 
The free margins also contain tendinous fibres, and behind the 
folds in the walls of the arteries are little pouches, the sinuses of Val- 
salva. When the valve is open, the nodules prevent the folds from 
being flattened against the tube ; but when the systole is over, a 
little of the reflux blood, with that already in the pouch, starts the 
folds towards closing, and the great reflux closes them with a sharp 
click. 

98. The Capacity of the cavities of a hollow muscular organ 
is difiicult to determine. The estimates given for the left ven- 
tricle vary from one hundred and twenty to one hundred and 
ninety-five grammes (four to six and one-half ounces). The 
capacity of the auricle is equal to or a little smaller than that of 
its ventricle. It is inferred that each contraction sends the same 
amount out of the right side as is sent out of the left. The heart- 
muscle receives its food from the aortic system, but the tissues ad- 
jacent to the endocardium may receive a small amount from the 
contents of the heart. The substance of the heart contains numer- 
ous nerve-ganglia, and upon its surface are sympathetic nerves and 
ganglia (386). It also receives fibres from the pneumogastric nerve 
(383). 

99. Tlie arteries are firm, membranous, cylindrical tubes, 
arising from the ventricles of the heart by two trunks : that 
from the left ventricle, named the aorta, is the systemic 



99. What are arteries ? Describe the aorta and its branches. 



64 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

trunk, and that from the right ventricle, named the pul- 
monic artery, is the lung trunk. 

The systemic trunk, or aorta, divides and subdivides into 
finer and finer arteries, like the branches from the trunk 
of a tree, excepting that these branches communicate with 
one another in a finer net-work, till the ultimate ramifica- 
tions, too minute to be seen by the naked eye, extend to 
every nook and corner of the body. These final branches 
are called capilkmes. 

100. The Capillaeies serve to connect the terminations 
of the arteries with the beginning of the veins, so that it is 
impossible to tell just where the artery ends and the vein 
begins. 

101. The Veins thus commencing with the capillaries 
unite into larger and larger veins, converging towards the 
heart, like the roots of a tree towards its trunk, till the 
final union in two trunks (the ascending and descending 
venae cavse), that connect with the right auricle of the heart. 

102. The Superior Vena Cava derives its branches 
from the heart, neck, upper extremities, and walls of the 
thorax. It terminates at the upper back part of the right 
auricle of the heart. The Inferior Vena Cava collects 
the blood from the lower extremities, pelvis, and abdomen, 
and terminates in the right auricle. 

103. The Portal Vein is a short trunk, about three 
inches in length, derived from the convergence of the 
veins of the stomach, spleen, pancreas, and intestines ; this 
passes into the liver, where it divides and subdivides, 

100. What is the use of the capillaries? 
lOL "What of the veins ? 

102. Speak of the superior vena cava. Of the inferior vena cava. 

103. The origin of the portal vein. Its distribution. Course of 
its blood. 



THE VASCULAR SYSTEM AND THE CIRCULATION. 65 

being distributed throughout the organ. This blood, with 
that of the hepatic artery, is returned to the general circu- 
lation by the hepatic veins. 

104. The Pulmonic or lesser circulation, from the right 
ventricle through the lungs to the left auricle, has a similar 
set of vessels: the trunk leaving the right ventricle is 
named the pulmonic artery, and corresponds to the aorta; 
those trunks conveying the blood to the left auricle, and 
corresponding to the venae cavse, are named the pulmonary 
veins. 

105. Arteries are strong, yellowish- white, branching 
tubes. They have thick, elastic walls, and consist of three 
coats. The outer coat is of firm areolar and elastic tissue 
(22) ; the middle, of unstriped muscular fibre (72), arranged 
circularly around the tube and elastic fibres ; and the inner 
is a very thin, smooth membrane. When cut across, an 
artery remains open. If a string is tied tightly around an 
artery, it crushes the inner and middle but not the outer 
coat, which is very tough. Hence, by the use of ligatures, 
severe bleeding from a vessel can be controlled until nature 
has time to close up the tube with a living plug. Arteries, 
especially in the extremities, frequently anastomose. Hence, 
if an artery becomes plugged by disease or operation, the 
blood can be carried around the obstruction to the part 
beyond. Arteries are usually placed deeply between the 
muscles, and are shielded by membranes and bones. 

106. The smaller arteries have relatively more muscular tissue, 
and the larger relatively more clastic tissue, in their walls. The 
outer coat, and perhaps the middle coat, is supplied with nutrient 



104. Speak of the pulmonic circulation. Of its arteries. Of its 

veins. 

105. Dcsoribc an artery. Its ooats. Its action wlion cut iioross. 
"What is a ligature ? AVhut is iinastoniosis ? Position oi jwtcrios ? 

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ANATOMY, PHYSIOLOGY, AND HYGIENE. 



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THE VASCULAR SYSTEM AND THE CIRCULATION. 67 



Fig. 29. 




Fig. 29. The Aorta and its BuANruKS, — 1, Tho coinmciioomont of tlic aorta. 2, The 
arch of the aorta. 3, Tlio carotid arti-ry. 4, Tlio temporal artery, o. The snl>ohivian 
arttiry. (!, The axilhiry artery. 7, The brachial artery. 8, The radial artery. \\ The 
ulnar artery. 10, The iliac artery. 11, The femoral artery. 12, The tibial artery. K?. 
Tho peroneal artery. 



68 



AND HYGIENE, 



blood-vessels, vasa vaso7^um. The arteries have nerve-fibres from 
the sympathetic system. Hence the diameter of the lumen of the 
arteries can be changed under the action of the nervous system 
upon the fibres of the muscular coat. By the sending out of cer- 
tain nerve-impulses, the muscular contractions diminish the lumen 
of the artery ; by the relaxation of the muscular tonicity, the action 
of the elastic tissue causes the lumen to be increased. Thus the 
flow of the blood in the smaller arteries and in the capillaries is 
regulated. 

107. The Veins have thinner walls and are more yield- 
ing than arteries. When 
cut across, they collapse. 
Within certain veins, at 
intervals, are found little 
folds or flaps, called valves. 
They are most numerous 
in the lower limbs, and as- 
sist materially in the flow 
of the blood. The small 
veins occur quite irregu- 
larly under the skin, but 
deeper in the tissues they 
accompany the arteries 
and bear the same names. 




Fig. 30 {Leidy). Diagrams exhibiting the 

ARRANGEMENT OF THE VaLVES OF VEINS. — A, 

Vein laid open, showing the valves in pairs. 
B, Longitudinal section of a vein, indicating 
the mode in which the valves, by apposition of 
their free edges, close its calibre. The dilated 
condition of the walls behind the valves is also 
seen. C, Vein distended, showing how the 
sinuses behind the valves become dilated. 



108. Valves are not found 
in the cranial, spinal, renal, 
portal, hepatic, or pulmonary 
veins. Their folds may be 

single, double, or triple. Their free edge is always towards the heart. 

Veins have vasa vasorum and a few nerves. 



H( 



is the flow of 



106. What is said of the smaller arteries? 
the blood regulated ? 

107. Differences between veins and arteries ? Valves ? Position of 
the veins? 



THE VASCULAE SYSTEM AND THE CIRCULATION. 69 

Experiment. — Tie a string around the forearm below the elbow, but not so tightly as to 
stop the radial pulse. The veins at the back of the hand soon become distended. Little 
venous prominences, about an inch apart, may be seen. These indicate vei-y nearly 
the position of the valves. On one vein press on the finger side of the valve, then stroke 
the blood to beyond the next valve, and the intermediate portion of the vein will lose its 
distention, — that is, the valve prevents the reflux of the blood. Remove the finger-press- 
ure, and the tube again appears, owing to the fact that the heart is constantly pumping 
blood into the veins. If the compression is continued for some time, the hand becomes 
painful, cooler, and bluish in appearance. Hence all obstruction to the venous flow of 
the blood is injurious. 

109. The fine net-work of minute capillary tubes in 
which the arteries end and the veins begin has very thin, 
nucleated, membranous walls. These walls permit the nu- 
tritive material of the blood to pass freely into the neigh- 
boring tissues and spaces (143). The heart, arteries, capil- 
laries, and veins form a closed system of . chambers and 
tubes, in which the blood is contained. 

110. The walls of the capillaries are formed by the fusing together 
of very thin and flat nucleated cells. The capillary net-work is of 
various forms, — in the muscles, elongated ; in the skin, loop-like ; 
in the intestines, close-meshed, etc. The tubes are the smallest, 
and the meshes finest, in the lungs. The smallest, however, permit 
the passage of the red corpuscles. The joint cartilages, the cornea 
of the eye, the enamel of the teeth, the epidermis, the nails, and 
the hair have no capillaries. 



BLOOD. 

111. Physical Appearances.— The blood in the 
living human body is a fluid varying in color from a brov^qi- 
ish red to a bright red. It has a peculiar odor. It consti- 
tutes by weight about one-thirteenth of the body: thus, a 
man weighing 75 kilograms (165 pounds) would have 
iabout 5.8 kilograms (12.7 pounds) of blood. 



109. What of the capillary walls? What pa?ses through their 
walls? Where may blood be found in the normal body? 
in. Appearances of blood ? The amount? 



70 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

112. Microscopic Appearances.— A drop of blood 
under the microscope shows a pale-yellowish fluid, plasma, 
in which float a large number of disks, corpuscles, of which 
the red are more numerous than the white. The red cor- 
puscles have rounded edges, are circular, are concave on 
the upper and lower surfaces, and when seen on edge 
appear dumb-bell-shaped. If 3400 w^ere placed side by 
side in a line, they would fill a linear inch; if about 14,000 
were placed one upon another, they would occupy a vertical 
inch. It is estimated that 83,000,000 exist in a cubic inch 
of normal blood. 

113. The red corpuscles have a homogeneous appearance, and 
show no nucleus. If they roll together they often assume an appear- 
ance like a roll of coins. The white corpuscles are not uniform in 
size, as are the red ; they are granular and contain a nucleus, they 
tend to adhere, and they are more abundant after meals. They fre- 
quently change their forms, and at times exhibit a remarkable ap- 
pearance, with changes of position, called amosboid movements (9, 6). 
Transparent net-works of fine fibres, called fibrin, are sometimes 
seen between the red corpuscles. 

114. Chemical Composition. — The living fluid consists of from 
one-third to one-half of its weight of corpuscles, and the rest of 
plasma. The gases oxygen, nitrogen, and carbonic acid are mechan- 
ically mixed with the blood. The plasma is made up of a small 
percentage of fibrin, C, H, O, N, S (4), and a yellowish fluid called 
serum. 

115. The serum is composed of water (H, O), ninety parts; serum- 
albumen (C, H, O, N, S), — a transparent fluid, very similar in ap- 
pearance to the white of an Qgg, — seven to eight parts; fats (C,H, O), 
extractives like urea (C, H, O, N), sugar, lactic acid, etc. (C, H, O), 
and salines, sodic and potassic chlorides (Na, K, CI), calcic, mag- 
nesic, sodic, potassic phosphates, carbonates, and sulphates (Ca, Mg, 

112. Microscopic appearances ? Describe the red disks. Their size 
and number. 

113. What of the red corpuscles? Of the white corpuscles? Of 
the amoeboid movements ? Of the fibrin ? 



THE VASCULAR SYSTEM AND THE CIRCULATION. 71 

Na, K, 0, H, P, C, S), one to two parts. The most abundant salines 
are the salts of sodium, especially common salt (sodic chloride). 

116. The red corpuscles consist of about fifty-seven per cent, 
water, and the rest mostly of organic solids, of which hoemoglobin 
(C, H, O, N, S, Fe) constitutes the larger part. This compound is 
the great iron- containing material of the body, and acts as the 
oxygen-bearer of the blood (180). 

117. The corpuscles contain the same salines as the serum, but 
the potassic salts and the phosphates are relatively in larger pro- 
portions. 

118. The exact chemical arrangement of the fourteen chemical 
elements (4), especially the atomic grouping of the carbon com- 
pounjds, is not known. The means of research now in use do not 
enable us to grope into the combinations of the living fluids and 
living solids of the body. Most of the chemical changes taking 
place in the living blood and tissues can, as yet, only be conjectured. 

119. The origin and fate of the corpuscles are debated questions. 
The red may arise from certain colorless nucleated bodies in the 
blood, similar to, if not identical with, the white corpuscles of the 
blood, from the small nucleated corpuscles of the spleen-pulp (298), 
or from the transitional cell-like forms seen in the red medulla of 
the large bones. The spleen is supposed to be the grave of many 
red corpuscles, and the breaking up of the corpuscles to form the 
biliary coloring- matter, the end of others. The white corpuscles 
may arise from division of the colorless cell-bodies, but more prob- 
ably from the lymphatic glands and other adenoid tissue (296). 
Their function appears to be to give birth to the red corpuscles. 

120. Coagulation of Blood.— If a little fresh blood 
is collected and allowed to remain in a clean vessel, it is seen 
to pass through a fluid, a viscid, and a jelly-like stage in 
turn; then a few drops of a yellow fluid appear on this 
jelly-surface, about tlie sides and below; finally, a central, 
dark, contracting mass floats in the yellowish fluid. This 
mass is called the clot. The process of clot-formation is 
called coagulation. 



120. Describe the changes occurring in blood-ooaoulation. Of wluit 
is clot composed ? Write out a scheme of the changes. 



72 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



Fluid Blood. 
Plasma. 



_Serum. 


Coagidated Blood. 
Serum. 


Fibrin. -__^^^ 




Corpuscles.. 


^~~-^ Clot. 



Corpuscles 

121. If a little fresh blood is whipped with fine sticks or wires, 
a fine felt-work of elastic, pale, granular fibres adheres to them. 
These fibres are fibrin. The clot consists of the corpuscles im- 
prisoned in the slowly-forming fibrin. 

122. Coagulation is favored by exposure to the air, motion, and 
the presence of obstacles and rough objects. Blood does not coag- 
ulate in the healthy living blood-tubes. It may coagulate in dis- 
eased, enlarged, or contracted blood-tubes, or in the heart. When 
a blood-tube is ruptured or cut across, as after an injury, the stream 
of blood is hindered, and in most cases arrested, by the forming of 
a clot. This is one of Nature's methods of stopping hemorrhage. 
Later, minute vessels appear in the plug, and it soon becomes organ- 
ized, and a part of the living blood-tubes : thus there is no recur- 
rence of the bleeding. 

123. Function of the Blood. — Blood is the great 
medium of interchange between the tissues. Thej are 
bathed and permeated by it. It takes to them the neces- 
sary foods, and removes from them their waste and effete 
matters, which it conveys to the proper excreting organs, 
as the kidneys, lungs, etc. Its fluidity enables it to pass 
through fine tubes into all organs. Its plasma passes through 
the healthy coats of the tubes into the cellular spaces. The 
vitality of the tissues depends upon the presence of this 
very complex fluid. Its chemical composition, and its 
physical appearance, color, density, etc., are constantly 
changing. The white corpuscles appear to have no special 
function; the red have a special respiratory duty (181) ; and 

123. What is the blood ? What does it accomplish ? What changes 
does it undergo? What are the functions of the red corpuscles? Of 
the white ? Of the plasma ? 



THE VASCULAR SYSTEM AND THE CIRCULATION. 73 

the plasma acts a nutritive part, as well as that of a cor- 
puscle and a gas-bearer. 

CIRCULATION OF THE BLOOD. 

Directions. — With tapes fasten a live frog on a jiiece of stiff card-board. Near the toes 
of one outstretched hind limb cut a hole in the card three-quarters of an inch in diameter. 
Attach threads to two adjacent toes. So arrange the threads that the stretched web comes 
over the centre of the hole. Place a drop of water on the web, and over the same a thin 
cover-glass. Use on the microscope a 1-inch or %-inch objective. If you desire greater 
magnifying power, lengthen the tube with blackened Bristol-board. Observe the moving 
bodies; the red and the ivhite corpuscles; the comparatively small number of the latter; 
the walls of the channels ; the rapid central current ; the slow wall-current ; and the 
pigmented granules in the web. 



Fig. 3L 



Fig. 32. 





Fig. 31 {After Wacjncr). A Piece of the Web of a Frog's Foot, slightly enlarged, 
showing the fine capillary net-work connecting the terminations of the arteries with the 
commencement of the veins. 

Fig. .32 (Allen Thomxon). A Minute Piece of the Maugin of the Froc/s AVkh, show- 
ing the ultimate capillaries, connecting the end of a small artery with the beginning 
of a minute vein. The oval blood-corpuscles are seen in these vessels, and the arrows 
entering and i)assing out of the artery and vein indicate the course of the blood-curront. 
Magnified about thirty diameters. 

124. Course of the Circulation. — The blood in the 
living body is always in motion. It moves in certain defi- 



124. What, of the blood in tlic livin«;- hody ? 
circulation. The pulmonic circulation. 
D 7 



Describe the svsteniii 



74 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

uite tubes and in certain directions. Propelled from the 
left ventricle J passing through the aorta and its arterial 
branches, the blood reaches the capillaries in every part of 
the body ; now entering the little veins which empty into 
the larger veins, it finds its way to the right auricle. This 
is called the systemic cikculation. Dropping into the 
right ventricle, it is propelled through the pulmonic artery 
and its branches to the lungs. Flowing through the capil- 
laries, it collects in the pulmonic veins, and, passing through 
the left auricle, it reaches the left ventricle. This is called 
the pulmonic circulation. 

125. The chief cause of the circulation of the blood is 
the contraction of the muscular walls of the heart upon 
its fluid contents. The motion is also influenced by the 
elastic and muscular walls of the arteries (105), the inter- 
mittent pressure of the body-muscles on their adjacent 
veins, and the movements of the chest in breathing. The 
effects of the muscular pressure are entirely due to the 
presence and direction of the valves in the interior of the 
veins. The influence of the respiratory movements on the 
circulation is very complicated, and cannot well be described 
in an elementary book. 

action of the heaet. 

Directions. — With tapes bind a living frog on the card-board or " frog-plate." Make 
an incision in the abdominal median line from the lower jaw to the pubis, and from the 
middle of this line two transverse cuts. Lift up the sternum, cut off its lower quarter, 
and then slit the sternum up to the neck. Pin back the right and left parts. The heart 
will be seen moving within its sac, the pericardium. Slit open the pericardium. Observe 
the contraction of the right and left auricles at the same time ; just later, the contraction 
of the right and left ventricles at the same time. During the contraction, or systole, the 
ventricle becomes pale, hard, rigid, conical, and the apex rises. Then occurs a pause, 
the diastole, during which the heart-chambers resume their uncontracted state. Again 

125. The chief cause of the motion ? Aids to the motion? Influ- 
ence of muscular action ? 



THE VASCULAR SYSTEM AND THE CIRCULATION. 75 



Fig. 38. 




Fig. 33. An ideal view of the circulation in the kings and system.— From the right 
ventricle of the heart (2), the dark, impure blood is forced into the pulmonary artery (3), 
and its branches (4, 5) carry the blood to the left and right lungs. In the capillary ves- 
sels (6, 0) of the lungs, the blood becoujes of a red color, and is returned to the left auricle 
of the heart (9) by the veins (7, 8). From the left auricle the pure blood passes into the 
left ventricle (10). By a forcible contraction of the left ventricle of the heart the blood 
is thrown into the aorta (11). Its branches (12, 13, 13) carry the pure blood to every part 
of the body. The divisions and subdivisions of the aiirta terminate in capillary vessels, 
represented by 14, 14. In those hair-like vessels the blood becomes dark -colored, and is 
returned to the right auricle of the heart (1) by the vena cava descendens (15) and vena 
cava ascendens (16). The tricusjiid valves (17) jirevent the retlow of the blood from the 
right ventricle to the right aiiricle. The semilunar valves (!}<) prevent the passage of 
blood from the pulmonary artery to (he right ventricle. The mitral valves ^19) prevent 
the reflow of blood from tbe left ventricle to the left auricle. The semilunar valves 
(20) prevent the roflow of blood from the aorta to the left ventricle. 



76 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

the auricles and the ventricles contract, and the large vessels become turgid udth blood. 
Note that after the auricle contracts the ventricle is redder and more distended than after 
the latter contracts. 

126. Action of the Heart. — The normal human 
heart contracts at regular intervals, ranging from sixty-five 
to seventy -five beats per minute in the adult. The right and 
left auricles contract together. The auricles contracting 
empty their contents into the ventricles. Almost imme- 
diately the tricuspid and mitral valves close and the ven- 
tricles contract, forcing the blood beyond the semilunar 
valves, which then suddenly close. A pause now occurs, 
during which the auricles fill with blood and the ventricles 
resume their uncontracted state. Then occur another 
series of contractions, a pause, a filling, and a dilatation. 
This rhythmic action commences in foetal life and con- 
tinues until the hour of death. The work of the auricles 
is light, that of the ventricles severe, and hence the latter, 
especially the left, have thicker walls. 

127. Work of the Heart. — At each beat it is sup- 
posed that the ventricles are entirely emptied. It is esti- 
mated that at each systole the left ventricle empties into 
the aorta one hundred and eighty grams (six ounces) of 
blood. A quantity equivalent to the whole blood passes 
through the heart in thirty-two contractions or beats. 
Supposing the heart to beat seventy-two times per minute, 
the day's work of the heart amounts to about seventy-five 
thousand kilogram-metres (about equal to the raising of 
one ton weight to the height of thirty-nine inches eighty- 
two times). The diastole is the period of rest for the heart- 

126. Describe the heart's action. What valves act at the same time ? 
What occurs during the pause ? What of the work ? 

127. The work of each beat? Frequency of the blood-passage 
through the heart ? The heart's work ? The heart's rest ? 



r 



THE VASCULAR SYSTEM AND THE CIRCULATION. 77 

muscle. For each beat it is nearly one-third of a second, 
or about nine hours per day. 

128. Heart-Inhibition" is the stopping or checking of the 
heart's pulsation. Colonel Townsend, by an act of the will, could 
hold his breath for such a length of time as to lessen his heart's ac- 
tion. Czermak, by pressing his pneumogastric (vagus) nerve (383) 
against a small bony tumor in his neck, could stop the beating of his 
own heart at will. An interrupted electric current passed over the 
vagi causes the beats to diminish, and even to cease. Mechanical 
and chemical stimulation of the divided nerve, or certain diseased 
conditions or injuries of the brain, may induce inhibition. The 
fainting from emotion or from severe pain is the result of a reflex 
inhibition acting through the brain on the vagi nerves. 

129. Acceleration of the pulsation of the heart may be in- 
duced by direct electric stimulation of the cervical spinal cord. 
The nervous impulses started by a sensation, an emotion, or a 
thought may accelerate or retard the heart's action. The introduc- 
tion of alcohol and of certain drugs into the system, acting upon 
the muscle, ganglia, or inhibitory apparatus increases the fre- 
quency of the beats ; some other drugs, on the contrary, retard the 
frequency of the pulsations. 

130. The modifications of the heart, through the influence of the 
vagi nerves and the general nervous system, enable this organ to 
accommodate itself to the varying demands and the changing con- 
ditions of the entire system. By means of the nervous system, the 
action of the heart and blood-vessels is co-ordinated. As the blood 
of the body is not sufficient to keep all the organs in full activity 
at the same time, and as only a part of the organs must be in full 
activity at a given time, the nervous mechanism of the heart and 
vessels, by modifying the force of the heart-beat and the calibre 
of the vessels, regulates the supply in accordance with the demands. 
When the digestive organs are in full activity, the brain works 
sluggishly, the nmscles do not contract vigorously, and certain 
minor functions arc in abeyance, for the nervous control limits tiic 
supply to the brain and nuiscles, but increases the supply to the 
intestinal organs. 

i;U. Heart-Sounds. O/wrra/iOH.— riiu-c Ihc hand on ilu> baro i-hivst of a bov ovor the 
fifth and sixth ribs, about two inohos to the loft of tin- stornuni. A slisiht concussion, 
the impnlse of the heart, is folt. This coincides with the >;/s/i>/<' of tlie ventrich>s. Tut 



78 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

two fingers on the wrist-pulse of the boy (the artery-beat may be felt on the thumb side 
of the wrist over the lower end of the radial bone, palmar side), and place the ear on 
the impulse-area: a deep, dull, long sound is heard at the time of the impulse and just 
before the pulse at the wrist. This is the first sound, and coincides with the ventricular 
systole and the closure of the mitral and tricuspid valves. Then place the ear to the left 
of the sternum over the space between the second and third ribs ; a sharp, high-toned, 
ringing, short sound is heard directly after the duller first sound. This is the second 
sound, and coincides with the closing of the semilunar valves. These sounds are some- 
what obscured by the sound of the rush of blood, the muscular sounds, and the impulses. 
With colored chalk or ink, mark on the skin the course of the main arteries of the neck, 
arms, and legs. Call special attention to the places over which the " field tourniquet" 
may be applied to control bleeding. (See Chapter XV.) 

132. Blood-flow in the Arteries. — When an artery 
is severed, the flow of bright red blood is not equable, but 
it comes in jets from the side towards the heart. These 
jets correspond with the heart-beats ; yet the flow does not 
cease between the jets. The larger the artery and the 
nearer to the heart, the greater the force of the jet and the 
more marked the intermittency. The velocity of the ar- 
terial stream is greatest in the large arteries, and dimin- 
ishes from the heart to the capillaries. Its average rate is 
estimated at twenty-five centimetres (about ten inches) per 
second in the common carotid. 

133. The rhythmic beat of the heart, combined with the resistance 
of friction in the tubes and points of branching and the smallness 
of the lumen of the capillaries, keeps the arteries in a state of 
permanent distention. Then each beat propels into the overfull 
artery a new increment of fluid, thus increasing the pressure and 
giving rise to an expansion of the elastic tube. When the beat is 
over, and the semilunar aortic valve's closure prevents the return 
of the fluid, then the elastic coat contracts, giving rise to a slight 
pulsation, followed by a continued pressure on the fluid. Hence 
the flow in the artery is intermittent from the heart's action, but 
the stream is kept continuous by the elastic after-pressure on the 
contents of the overfull arteries. 



132. The blood-flow from an artery ? What of the intermittency 
and force ? Of the rate of motion ? 



THE VASCULAR SYSTEM AND THE CIRCULATION. 79 

134. Vaso-motor Action. — The middle coats of all arteries 
contain circularly-arranged plain muscular fibres (72). Nerve-fibres 
from the sympathetic system (386) are distributed largely to the 
arteries. Experiments show that by the mechanical stimulation of 
certain of these nerve-centres the arterial muscular coat may be 
made to contract, causing the calibre of the arteries influenced to 
become smaller. Then, if the stimuli be removed, the muscular 
contraction diminishes, the elasticity of the vessel-wall increases the 
lumen, and more blood passes through the vessel. In snowballing, 
the contact of snow with the hand so affects the nerve- centres con- 
trolling the distribution of the blood to the hand as to diminish the 
arterial lumen. Later, this new action is overcome, the centres lose 
power over the muscular fibres, and the vessels become unduly 
dilated, giving rise to the increased glow and warmth of the skin. 

135. Experiments indicate that a centre of vaso-motor activity, 
presiding over and regulating the local centres, exists in the medulla 
(373), and regulates the calibre of the vessels of the system at large 
by keeping the muscular fibres of the vessels in a state of tonic con- 
traction ; that the blood acting on this centre causes the generation 
of certain impulses which incite the muscular fibres to greater 
or less contraction, thus modifying the calibre of the vessels, and, 
as a result, the amount of blood sent to a part is gauged to the 
wants of that part. Experience shows that the vaso-motor centre 
and the local centres may be depressed or exalted by varying influ- 
ences coming from the various sentient surfaces or the brain. When 
the right hand is dipped in cold water, the temperature of the left 
hand falls, owing to a reflex constriction of the vessels of the skin 
of that hand ; when one eye is injured, the other not infrequently 
becomes diseased, being a result of reflex vaso-motor action ; when 
a certain thought or emotion arises in the brain, it depresses or 
exalts that portion of the vaso-motor centre controlling the vessel- 
areas of the neck, and thus blushing or pallor is induced. The 
thought of food often causes an increased amount of blood to bo sent 
to the glands about the mouth, inducing a copious secretion of saliva, 
— i.e., " the mouth waters." 

136. The amount of the constriction of the minute arteries may 
in a great measure be dependent on the blood-pressure itself, though 
this is not fully demonstrated. There are reasons for believing- that 
the vaso-motor centre is directly afl'ected by the quality of the blooii 



80 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

passing through it. If the quantity of oxygen in the blood is 
reduced, the contraction of the muscular fibres of the vessels is 
increased, and arterial constriction, with a rise of blood-pressure, 
results. If the oxygen is increased, the action of the centre is less- 
ened, the vessel is dilated, and the pressure falls. 

137. The vaso-motor system is of great regulative value. By local 
dilatation in one area the flow of blood is encouraged, and the 
consequent reduction of pressure lessens the amount of blood sent 
to other areas. By local constriction in one vascular area the blood- 
pressure is raised, the calibre of the vessels is diminished, and the 
mass of the blood is thus forced to other areas. These vaso-motor 
centres respond to external or to internal stimuli, acting through 
the blood or the nervous tracts, and thus the supply of blood to this 
or to that organ or tissue is regulated. In cold weather the vessels 
of the skin are constricted, the flow of blood is diminished, and thus 
undue loss of heat is prevented. In warm weather the cutaneous 
vessels dilate, the blood-flow to the skin is increased, the pei-spira- 
tion is augmented, and the loss of heat from the skin is thus en- 
couraged. In health, the harmonious inhibiting and exalting of 
these centres keep the mass of the blood in those parts where it 
is most needed. 

138. Colds are very frequently caused by a portion of 
the skin being exposed to a current of cold air, or by the 
wearing of damp clothing. The nerves of the skin, acting 
on the vaso-motor centre (135), incite the latter to send 
forth such impulses to the muscular coats as lead to a dimi- 
nution of the calibre of the cutaneous vessels. This causes a 
rise in the blood-pressure, and the crowding of an abnormal 
amount of blood into the internal organ areas, inducing in- 
ternal "determination of blood,'' followed by "congestion." 
Tlie internal overplus of blood is made known to us by a 
feeling of uneasiness, followed by a more or less copious 
discharge of mucus and fluids, — in the cold season by bron- 
chitis and nasal discharge, in the warm season by diar- 

138. The cause of colds ? The influence of the vaso-motor centre ? 
Results of the overplus in certain areas ? The proper treatment ? 



THE VASCULAR SYSTEM AND THE CIRCULATION. 81 

rhoea. Hence in such maladies we seek to induce the skin 
vascular areas to receive more blood, by employing friction, 
external heat, extra merino under-clothing, and a flannel 
band (eight or ten inches wide) for the abdomen. 

139. Blood-flow in the Capillaries. — Tlie flow 
is constant, equable, and regular. The motion is most 
rapid in the centre of eacli stream. The velocity has been 
estimated at one-thirtieth of an inch per second in the sys- 
temic capillaries, and one-fifth of an inch per second in the 
pulmonic capillaries. This slow rate aflbrds time for the 
interchange between the blood and the air in the lungs. 

140. The retardation of the flow is due to the increased capacity 
of the capillary area over the arterial common trunks. The arterial 
blood-pressure is always greater than the venous, and the blood 
flows through the capillaries to the part offering the least resistance ; 
that is, towards the veins. The heart-beat pulsation is not trans- 
mitted to the capillary current. The elastic rebound of the arterial 
walls crowds the overplus of each ventricular systole in a steady 
stream into the venous system,- and, by a nice adjustment of the 
nerve-influence of the vaso-motor centres, as much blood is dis- 
charged into the veins as is received at each systole. If the heart 
ceases to beat, the elastic walls of the arteries force enough blood 
through the capillaries to equalize the pressure of the arterial and 
venous systems, and then all motion ceases. Hence, after death the 
large arteries are found nearly empty. 

141. Blood-flow in Veins. — When a vein is severed, 
the dark blood flows from the end near the capillaries in a 
continued stream, with little force and slight velocity. ' The 
velocity increases from the capillaries towards the heart. 
The velocity of tlie flow is said to average from one-third 
to one-half of that of the corresponding arteries. 



139. The flow of blood in the ciipillarios ? Its velocity? Wliftt 
changes occur ? 

14L The flow of blood from a cut vein ? The velocity of the venous 
flow? 



82 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

142. The primanj force in the movement of the blood in the veins 
is the heart's action, modified by the elasticity and recoil of the 
arteries. The movements are aided by pressure of the muscles 
acting on the veins having valves, and the thoracic respiratory 
movements. Expiratory movements, as coughing, sneezing, hold- 
ing the breath, retard the venous flow. The inspiratory movements 
facilitate the entrance of the blood to the auricles, but not to the 
ventricles, because of the semilunar valves. The rate of motion in 
the veins is more subject to disturbing influences, as rapid or slow . 
breathing, pressure of garments, bands, boots, gloves, etc., than any 
other part of the circulation. 

143. Interchanges in the Capillary Net-work. 

— All the tissues of the body live on the blood of the 
body. It is in the capillary areas that the blood is the seat 
of constant additions and constant subtractions. It is 
while slowly moving here that the blood does its nutrition 
and de nutrition work. By some as yet unknown process, 
each tissue selects and withdraws from it the materials 
which it requires, and gives up to it effete materials to be 
conveyed away. We only know that the blood coming 
from the capillary areas is different from that entering, and 
that definite changes have occurred, as is shown by repair, 
by growth, or by continued ability to perform functions. 

144. The Pulse is the name given to the impulse trans- 
mitted to a finger placed lightly upon an artery running 
over a bone, as the radial at the wrist, or the temporal in 
front of the ear. It is due to the intermittent additional 
distention which the artery experiences after each systole of 
the ventricles. In health it is present only in the arteries. 

145. Proofs of the Circulation are the anatomical 

143. What occurs in the capillary area ? What do the tissues do ? 
How is the blood changed ? What result in the tissues ? 

144. What is the pulse ? Its cause ? 

145. Proofs of the circulation in the living body ? What did 
Harvey prove? What did Malpighi see ? 



THE VASCULAR SYSTEM AND THE CIRCULATION, 83 

connection and the continuity of the heart, arteries, capil- 
laries, and veins (109) ; the different direction in which the 
blood escapes from a cut artery (132) and a cut vein (141); 
the effect of ligature upon the veins (108) ; the direction 
of the valves of the heart (92) and veins (107) ; and the 
observation of the blood moving in the web of the frog's 
foot (Fig. 32), and retina (451) of the human eye. In 
1628, William Harvey, of England, demonstrated the real 
course of the blood; in 1661, Malpighi demonstrated the 
capillary circulation in the web of the frog's foot ; and 
the problem which had baflQed their predecessors was then 
first settled. 

HYGIENE. 

146. The clothing should be loose, especially about the 
neck and limbs, in order that the flow of blood in the great 
venous vessels be not impeded in the least. In changeable 
weather woollen under-garments should always be worn, 
thus preventing the undue accumulation of blood in one 
part of the body at the expense of other portions. By the 
use of the flannel abdominal band during warm weather, 
diarrhoea can usually be avoided ; by the judicious distribu- 
tion of the clothing on the limbs and trunk, many coughs, 
colds, and subsequent maladies can be prevented. 

147. Persons suffering from diseases of the vascular 
system should take a proper amount of exercise daily ; 
should eat plain, nutritious food ; should avoid tea, tobacco, 
and also mental disturbance and all hasty, sudden exer- 
tions. Alcoholics ought not to be used, as they derange the 

146. What relation has the clothing to the veins? Why should 
woollen he preferred ? What of the ahdoniinal llannel hand? 

147. What of the management of disease of the heart or blood- 
vessels ? Speak of the effects of alcohol on the oirculatiou. 



84 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

vaso-motor system. The action of the heart is disturbed, 
the pulsations are increased, and hence results increased 
work for this vital organ. Alcoholics also relax the capil- 
laries, especially those of the skin and the nervous system, 
causing an early sense of warmth and exhilaration. This 
abnormal accumulation of blood in the skin and the nerve- 
centre areas deprives other areas of their proper share. The 
temporary exhilaration, mental and physical, is commonly 
followed by a corresponding depression, more especially 
under exposure to cold (245). Frequent repetitions of the 
unnatural over-distention of the nervous capillary areas 
tend to produce permanent perverted nutrition and dis- 
eased action in the nerve-centres, as is strikingly shown in 
alcoholism (408). 

147a. Ethyl-alcohol in the blood interferes with the " ripen- 
ing" of the crude materials derived from the food (306). It di- 
minishes the mobility of the corpuscles (209a), removes oxygen 
from the haemoglobin, and hinders the elimination of the carbon 
and nitrogen wastes. Hence the blood becomes laden with crude 
materials, tissue wastes, and tissue poisons (243). It is said to 
change the form, to lessen the size, and to diminish the number of 
the corpuscles. " Alcohol poisons the blood, arrests the develop- 
ment of the corpuscles, and hastens their decay" {Virchow). A 
degenerate or ill-conditioned blood, circulating in all parts of the 
system, induces abnormal nutrition (67a). Abnormal nutrition is 
always followed by abnormal or perverted actions — physical, men- 
tal, and moral (408). 

Fatty Degenei^ation. — Alcoholics regularly used, especially malt 
liquors, cause gland cells, the contractile sarcotic elements (71) 
of the heart muscles, and the elastic elements of the arterial walls 
(105) to become inert fat. This fatty change may occur in the 
skeletal muscle (516). The degenerative changes weaken the 
heart. It becomes unable to perform full duty, often enlarges, 
and may suddenly suffer rupture. The fatty change occurring in 
the arteries is often the starting-point of arterial obstruction, 
apoplexy, and aneurism. 



CHAPTEE yi. 

THE KESPIRATORY APPARATUS AND RESPIRATION. 

Direction for Dissection. 

When the thorax of a dog or rat is opened (88), air enters the pleural cavities ; the 
lungs, which had hitherto filled the large right and left chambers of the thorax, shrink 
somewhat. Before removing the thoracic viscera, bend two straws of broom-corn into 
a sickle shape, pass one into each nostril, and then urge them gently forward to their 
whole length. Open the mouth, gently move the soft curtain attached to the back part 
of the roof of the mouth to one side, and the two straws will be seen projecting into a 
cavity or open sac, the pharynx. The passages in which the straws lie are separated from 
each other by a long and cartilaginous septum, and from the mouth by bone and a soft 
fleshy curtain. The latter is called the uvula, or soft palate, and the former the liard 
■palate. If the musculo-membranous phai-ynx be laid open, five openings will be easily 
seen : two leading to the nostrils, one to the mouth, one to the larynx, and one to the 
gullet. The fleshy uvula is seen to be capable of closing either the passage to the nos- 
trils or that to the mouth, while the stiff, nearly vertical epiglottis can close down over 
the entrance to the larynx if pressed upon. At rest the mouth is completely filled and 
the entrance to the oesophagus is closed. 

Remove the larynx, trachea, lungs, and heart, as directed in Chapter V., 88. At the 
upper or anterior part we encounter the larynx, an irregular cartilaginous box, opening 
above into a membranous sac, the pharynx, and below into a cartilaginous tube, the 
trachea. Observe on the upper front of the larynx a stift", elastic, projecting, tongue-like 
mass, the epujlottis. Press this down, and it is seen to close over a slit-like opening in the 
larynx, the glottis. Lay open the larynx by an incision on the oesophageal side. The 
broad right and left cirtilages, the thyroid, and the cut edges of the lower ring-like car- 
tilage, the cricoid, are brought into view. In the interior, from above downward, note : 
the niucns on the surface, the two contiguous surfaces forming the upper slit, two right 
and left pits, the ventricles of the larynx, and two thin, contiguous surfaces, forming the 
true vocal coi'ds, and the cut cricoid, with the two arytenoid cartilages resting tlioroon. 

The trachea is found to be nearly a complete open tube. The front three-fifths of this 
tube is of horsoshoe-shapcd cartilages, while the posterior portion and the uniting parts 
of the semi-rings are made of fibro-muscular elastic membranes. The trachea divides 
into two partly cartilaginous tubes, the bronchi, which in turn, as a rule, divide and sub- 
divide by twos. The cartilages in these latter soon disappear, they only being represented 
by niembrane. The hunen of these tubes grows smaller and smaller, and is lost to sight 
in the soft, elastic, pinkish mass called the lung. Entering the Inng-mass, side by side 
with the bronchi, are seen the open, firm arterial tubes, and the numerous dark, thiti, 
flattened veins. These bronchi, arteries, and veins, together with the accompanying 
nerves, lymphatics, and connective tissue, constitute the root of the liimj. The smooth 
outer surface of the lung-mass is the j>ulnto)iary jdeitra. 15y a dainty scratch a portion 
of a thin membrane, the pleura, may be raised into view. The smooth lining of the 

8 85 



SQ ANATOMY, PHYSIOLOGY, AND HYGIENE. 

empty thorax is the parietal pleura, and the moisture the pleural fluid. Squeeze a portion 
of fresh lung-mass, and there arises a sensation called crepitation; throw a bit into water, 
and it is seen to float ; hold a bit under water, squeeze it, and bubbles will be seen to 
arise, — the residual air of the lung. 

Microscopic Work.— Cut out cubes of the soft tissues, and place in alcohol of 45 per 
cent. Examine the lung-tissue after careful teasing. Make thin sections of the car- 
tilages, and examine at leisure. 



THE THORAX. 

148. The Thorax is made up of an open cage-work of 
bones and cartilages, with the intervals filled w^ith muscles, 
membranes, tubes, and other soft parts. The bones con- 
sist of twelve bones of the verteh^al column behind, twenty- 
four ribs (twelve pairs), extending to the right and left 
from the column, and the flat, thin, and broad steimum 
in front. 

149. The Vertebral Column (343) is composed of a 
series of bones, called vertebrw, and disks of firm elastic 
material placed between the vertebrae, called the interverte- 
bral cartilages. The vertebrae are bound together by flexi- 
ble, elastic, and inelastic ligaments (509), and hence limited 
motion is possible, as in bending or twisting the spine. In 
the thorax the spine curves backward. 

150. The Ribs are long, flat, round-edged, curved bones. 
Behind they are attached to pits in the vertebrae, from 
whence they curve downward and forward. The upper 
ribs are most curved. The seven upper pairs are attached 
directly to the sternum ; the three next pairs indirectly, by 
means of long cartilages ; while the two lowest pairs are 
free in front. 



148. Speak of the thorax. The bones of the thorax. 

149. What of the vertebral calumn ? Of the cartilages ? Of tho 
ligaments ? Of the motions ? 

150. Describe a rib. How attached? Kinds of ribs? 



THE EESPIKATORY APPARATUS AND RESPIRATION. 87 



Fig. 34. 




Fig. 34. A Front Vikw of tiik Onr.ANS of the Oiust and Ardomen. — 1, 1, 1. 1, Tho 
muscles of tho chest. 2 2, 2, 2, The ribs. 3, 3, 3, Tlio upper, middle, and lower lobes of 
the right luna;. 4, 4, The lobes of the left lunjv. 5, The right ventricle of the heart. C, 
The left ventricle. 7, The right auricle of the heart. 8, The left auricle. 9, Tho pul- 
monary artery. 10, The aorta. 11, Tlie vena cava descendens. 12, The tmchea. 13, 
The oesophagus. 14, 14, 14, 14, Tho pleura. 13, 15, 15, The diaphragm. 16, 16, The right 
and left lobes of the liver. 17, Tho gall-cyst. 18. The stomach. 26, The spleen. li>, 19, 
The duodenum. 20, The ascending colon. 21, The transverse colon. 25, The descend- 
ing colon. 22, 22, 22, 22, The small intestine. 23, 23, The abdominal walls turned dowu. 
24, The thoracic duct, opening into the left subclavian vein. 



88 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



151. The Sternum is flat and broad. It has eight pits 
on each side, seven for the ribs and one for the clavicle^ or 
collar-bone. 



Fig. 35. 




Fio. 35. The Feoxt View of the Thorax.— 1, 2, 3, The sternum. 4, 5, The spinal 
column. 6, 7, 8,. 9, The first rib. 10, The seventh rib. 11, Cartilage of the third rib. 
12, The floating rib. 

152. The cage-work of bones is filled in with twenty- 
two pairs of muscles {intercostcds) which run obliquely 
between the ribs. The contraction of the eleven outer 
pairs aids in the enlargement of the thorax; of the eleven 
inner pairs, in lessening its capacity. 

153. The form of the thorax is conical. It is narrowest 
above, where the tubes and soft parts going to the neck 



151. Describe the sternum. 

152. How many thoracic muscles? Speak of the external set. 
Of the internal set. 

153. Form of the thorax? What of the diaphragm? What tubes 
perforate it ? 



THE RESPIRATORY APPARATUS AND RESPIRATION. 89 

nearly close it. It is widest below, where it is separated 
from the abdomen by the diaphragm. The latter is a 
broad, thin, almost circular muscle, having in its central 
portion some fibrous tissue. It arches up in the thorax, 
because of the constant pressure of the abdominal viscera 
and muscles. 

154. The chief contents of the thorax are the heart and 
lungs. These are the great central organs of circulation 



Fig. 36. 



Fig. 37. 





Fig. 36 {Leidy). Diagram exhibiting the Relative 
Position of the Common Anatomical Elements of Secrict- 
ING Membranes. — 1, Eijithelium, composed of nucleated 
cells. 2, Subjacent layer. 3, Areolar layer, in which the 
arteries and veins (4) ramify in a capillary net-work. 

Fig. 37 {Leidy). Diagram exhibiting the Relation of a 
Serous Membrane {the pleura) to the Organ it Invests and 
THE Cavity it Lines.— 1, Lung. 2, Root of the lung, which is the only attached por- 
tion of the organ, all others being free. 3, Side of the thorax. 4, Diaphragm. 5, Pari- 
etal pleura. 6, Pulmonary or reflected pleura. 7, Cavity of the pleura. Magnified. 

and respiration. The lungs occupy the right and left sides, 
and the heart the left central portion. The former are 
found in the pleural cavities, and the latter in the peri- 
cardial cavity. 

155. The Pleura is a thin, moist membrane, in the 
form of a closed sac, enclosing a fluid called serum. A 
portion of the outside of one sac is closely attached to the 
outer surface of one of the lungs and its root, and the other 
portion to the inside of its })r()per thoracic wall, while the 



154. Contents of thorax ? What cavities ? 

155. What is the pleura? Use of scrum? 



90 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

serous enclosed fluid lubricates the pleural surfaces, per- 
mitting the lung-portion to move smoothly over the tho- 
racic portion. Tlie lung is therefore outside of the sac 
of its pleura. The pleurae are two in number, and form 
two chambers. 

Fig. 38. 




t 

Fig. 38. Vertical Section, c, Cavity of skull. /, Falx. s, Spinal canal, leading 
from cavity of skull, n. Right nasal cavity. Below the hard and soft palate, the cavity 
of the mouth, the teeth, tongue, and lips, p, Pharynx, o, (Esophagus, h, Section of 
hyoid bone. I, Larynx, e, Epiglottis, t, Trachea, v, Section of cervical vertebrae. 
(Mar&hall.) 

156. A SEROUS MEMBRANE consists of epithelial cells, a delicate 
subjacent web of tissue, on which the epithelia rest, and some 
areolar tissue (22) beneath, containing the blood-vessels and nerves. 
The epithelial cell consists of a delicate limiting structure, enclosing 
protoplasm, which contains nuclei and granules. Serous membranes 
usually have a single layer, being most frequently of the pave- 
ment variety (Fig. 42). The subjacent tissue, or basement mem- 



THE RESPIRATORY APPARATUS AND RESPIRATION. 91 

brane, in cross-section appears little more than a faint line. The 
protoplasm of the epithelia elaborates a thin, slightly albuminous 
fluid, called serum. This kind of membrane is formed into a closed 
sac, having the epithelia on the inside. The principal membranes 
of this class are the pleura, the pericardium (95), and the peri- 
toneum (246). 

THE AIR-PASSAGES. 

157. The Nasal Passages are two in number. They 
are separated from each other by the bony and cartilaginous 
septa of the nose, and from the moutli by the hard palate 
and the soft palate, or uvula. They open behind into the 
pharynx. They are lined by mucous membrane, which is 
very vascular. In the upper portion of these passages are 
located the nerves of smell (429). (Fig. 38.) 

158. The Pharynx (259) is a musculo-membranous 
open sac. It is wider above than below, and is suspended 
from the base of the skull like a bag under a grain-funnel. 
It has seven openings, — above the soft palate, the two lead- 
ing forward to the nostrils, the two to the middle ears 
(Eustachian tubes); below the soft palate, one to the mouth, 
one to the oesophagus, and one to the larynx. 

159. The Soft Palate descends like an apron from 
the back edge of the hard palate, and is largely composed 
of muscles. The mucous membrane covering it above is 
like that of the nasal passages; below, like that of the 
mouth. The uvula can close either the opening to the 
nasal passages or the opening from the pharynx to the 
mouth (Fig. 38). 

160. The Larynx (487) is a hollow chamber, which is 

157. Nasal passages ? Boundaries? Openings? Lining? 

158. Describe tlie pharynx. Its openings. 

159. What of the soft palate? Its membrane ? Its duty ? 

160. "What is the hirynx? Openings? Structure? Duty of the 
epiglottis ? 



92 ANATOMY, PHYSIOLOGY, A:N^D HYGIENE. 

suspended from the liyoid hone at the base of the tongue. 
It opens into the pharynx above and the trachea below. 
The framework is made up of cartilages held together by 
small ligaments, and forms the projection called " Adam's 
apple." At the upper opening is a curved, upright, elastic 
plate, called the epiglottis, which, during swallowing, closes 
down over the entrance to the larynx and prevents the 
admission of foreign materials. 

161. The Trachea is situated in the middle line of 
the neck, commencing at the larynx and terminating in 
two smaller tubes called bronchi. It is from three-fourths 



Fig. 39. 



Fig. 40. 





Fig. 39. The Bronchia.— 1, Outline of right lung. 2, Outline of left lung. 3, 4, 
Larynx and trachea. 5, 6, 7, 8, Bronchial tubes. 9, 9, Air-cells. 

Fig. 40. (Leidy). Diagram of Two Primary Lobules of the Lungs, magnified. 1, 
Bronchial tube. 2, A pair of primary lobules connected by fibro-elastic tissue. 3, Inter- 
cellular air-passages. 4, Air-cells. 5, Branches of the pulmonary artery and vein. 

of an inch to one inch in diameter, and is always open. 
It is made up of from sixteen to twenty independent, trans- 
verse, incomplete rings of cartilage, which are held together 



161. Describe the trachea. Its position. 



THE RESPIRATORY APPARATUS AND RESPIRATION. 93 

by muscular and elastic fibres. Behind, the tube is com- 
pleted by a musculo-fibrous membrane. 

162. The Bronchi are tvyo in number. Their structure 
is similar to that of the trachea, the cartilage hoops being 
incomplete. On entering the lungs the bronchi divide and 
subdivide, usually by twos, into smaller tubes, called bron- 
chiaj and then the whole appears like a tree with many 
branches. In all the larger and medium-sized bronchia, 
bits of cartilage are interspersed in the elastic fibrous mem- 
brane of the walls, in order to keep the tubes open. 

163. Air~Cells. — The finest bronchia divide within 
the lobules of the lung from four to nine times. These 
finally terminate in the air-sacs. These air-sacs have nu- 

FiG. 41. Fro. 42. 





Fig. 41. Diagram of a Veetical Section of the Bronchial Mucous Membrane.— 
1, Columnar ciliated epithelial cells. 2, Cilia. 3, Nuclei. 4, Young cells. 5, Basement 
membrane. 6, Fibrous layer. 

Fig. 42 {Leidy). Pavemrnt Epithei.htm, from a serous membrane, highly magnified, 
and seen to consist of flat, six-sided nucleated cells. 



merous cup-shaped depressions, called air-cells. The walls 
of the cells, in which blood-vessels, lymphatics, and nerves 
ramify, are transparent and very thin, and are lined with 
a delicate mucous membrane. 



162. What are the bronchi? The bronchia? Function of tlie 
pieces of cartihige ? 

163. Speak of the air-cells. Form. Walls. 



94 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

164. The air-passages from the nose to the air-cells are 
lined by mucous membrane. Throughout most of the 
tubes it has an epithelium (156), showing free-moving, 
hair-like projections, called cilia (74). In a portion of the 
pharynx and in the air-cells the epithelia of this membrane 
elaborate a watery material, more or less viscid, called 
MUCUS. In places within the air-passages are glands, 
which secrete a thicker and more abundant mucus. 

165. The mucous membrane consists of one or more layers of epi- 
thelium, resting upon a transparent and delicate subjacent or base- 
ment layer of tissue. This merges beneath in a layer of areolar and 
elastic tissue, in which ramify blood-vessels and nerves (Fig. 36). 
Mucous membranes open directly or indirectly on the surface of 
the body. The chief and most extensive one is called the gastro- 
pulmonary, because it forms the lining membrane of the digestive 
apparatus and the air-passages. 

166. Mucous glands. — In some parts of the trachea, bronchi, and 
bronchia the mucous membrane is recessed into little tubes or sacs, 
which are called glands (250). The secreting surface is thus very 
much increased in a small space. The mucous crypts of the air-pas- 
sages secrete an abundantly thick bronchial fluid, called bronchial 
mucus. The protoplasm of the epithelia is the secreting agent (156). 

167. The Lungs are two in number, and occupy com- 
pletely and accurately the pleural chambers of the thorax. 
Each lung is free in all directions, except at the root, which 
chiefly consists of the bronchi, arteries, and veins connect- 
ing the lung with the trachea and the heart. The lungs 
are porous, spongy organs, the tissues of which are very 
elastic. 

168. Each lung is of a conical shape, the apexes of which are 
blunt and project into the neck from an inch to an inch and a half 

164. What lines the air-passages ? Kinds of epithelia ? Their 
secretion ? G-land-secretion ? 

167. Speak of the lungs. Position. Eoot. Structure. 



THE RESPIRATORY APPARATUS AND RESPIRATION. 95 

above the first rib. The base is broad and concave, and rests on the 
diaphragm (153). Each lung is divided by a deep fissure into upper 
and lower lobes. The upper lobe of the right side is imperfectly 
divided into two lobes, making^ three in the right and two in the 
left lung. The lobes are made of many closely-packed lobules. 
Each lobule is composed of a terminal branch of an air-tube, pos- 
sessing a cluster of air-cells. In the fine interstitial areolar tissue 
of the lobule ramify the pulmonary vessels, the nutrient vessels, the 
lymphatics, and the nerves (Fig. 40). 

1 69. The Capacity of the chest, and, therefore, of the 
lungs, varies. In a man of average height, after a forced 
inspiration, the chest contains about 5380 cubic centimetres 
(328 cubic inches) of air. After a violent expiration, fol- 
lowed by a violent inspiration, a healthy man of average 
stature (five feet eight inches) can take in about 3700 cubic 
centimetres (225 cubic inches). This is known as his vital 
capacity. This amount increases by about one hundred and 
thirty cubic centimetres (eight cubic inches) for each inch 
of stature above the average. In ordinary breathing, five 
hundred cubic centimetres (thirty cubic inches) of air are 
taken in and expelled with each complete respiration. 

Directions for Demonstrations. — Let a healthy boy remove the apparel covering his 
neck and chest, except a close-fitting undershirt. Have him stand easily erect and exe- 
cute four or six full respirations in a deliberate manner, the class, meanwhile, watching 
the movements attentively. 

Place a tape snugly around the chest, about three inches below the armpits. Notice 
the difference in circumference during a full inspiration and a complete expiration, — 
1st, in normal breathing; 2d, in labored breathing. Notice that the right half-circle of 
tlie chest is usually larger. If a spirometer can be procured, test the aii'-capacity of the 
lungs. Place the forefinger flat on the wall of the chest. Tap this finger smartly with 
the first two fingers of the other hand. Test different parts of the chest in front and in 
tiie rear in the same manner. A clear sound denotes the presence of air in the organs 
beneatli : a dull sound, the presence of solids or liquids. The healthy lung-areas give 
forth a clear sound. By this method, the limits of the huigs, the heart, the liver, and 
the intestines may be approximately mapped out. 

Place the oar on the skin over the region of the trachea in front ; a blowing so\ind is 
heard both in inspiration and in expiration. Then place the ear on the shirt, over the lung- 



169. Capacity of the chest after inspiration? Vital cai^aoity? 
Ordinary variation ? 



96 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

areas, pressing the latter smoothly and closely on the chest-walls. Listen in one place 
during several respirations. Shift the ear to different parts of the chest, and listen. A 
soft, low, murmuring sound is heard, being most marked over the front and upper parts 
of the chest and during inspiration. The murmur is mainly caused by the air passing 
in and out of the air-sacs and air-cells. 

Take a clean glass (fruit) jar with cover ; fasten a piece of candle, with wire or a small 
nail, near the end of a stick twenty inches long. Lower the lighted candle into the jar: 
it will burn freely. Reverse the jar; shake after the taper is withdrawn. Now have 
some person take a full inspiration, retaining the air, for a time, in the lungs; then 
steadily expel it from the lungs into the jar, directing the current to one side; cover; 
soon breathe again in the same manner into the glass vessel, and lower a lighted candle. 
The flame will be extinguished, because the carbonic acid, the watery vapor, and other 
gases from the lungs have so vitiated the air in the jar as to prevent combustion. Such 
air will not sustain life. (Before entering deep wells or caverns, a lighted taper should 
be lowered.) Place a little fresh lime-water in a jar ; breathe several times into it ; cover, 
and shake the lime-water. Instead of a clear liquid, there will be formed the white car- 
i)onate of lime. Put a live rat in a jar. Regulate the supply of air by the cover, giving 
a liberal supply, a limited supply, and then total exclusion of air, and notice the results. 

Breathe on the cool surface of a clean mirror, and watery vapor will be condensed from 
the saturated exhaled air. Take a clean, cool mirror into the recitation-room. In a few 
minutes examine the moist surface. If onions or leeks have been recentlj' eaten, ether 
or chloroform inhaled, or alcoholics recently drunk, or if persons have decayed teeth, 
the expired air will give forth odors easily detected. When air vitiated by respiration 
passes through strong sulphuric acid, the latter becomes darkened; through a solution 
of permanganate of potassa, the solution is bleached; through distilled water, the 
water becomes offensive in odor' and taste. These tests show the changes produced in 
air by respiration. 

PHYSIOLOGY OF RESPIRATION. 

170. Enlargement of the Thorax. — In normal 
breathing there are two principal means of enlarging the 
internal capacity of the thorax : the descent of the dia- 
phragm and the elevation of the ribs. When at rest, the 
muscular diaphragm is arched into the thorax ; but when 
contracted, it becomes flatter (Figs. 43, 44). Tliis move- 
ment of the diaphragm presses upon the abdominal con- 
tents, causing the abdominal walls to project, but enlarging 
the capacity of the chest from above downward. The 
elevation of the ribs enlarges the front-to-back and side-to- 
side diameters of the chest. Abdominal or diaphragmatic 

170. Means of enlarging thoracic capacity ? Action of diaphragm ? 
Elevation of ribs? Abdominal inspiration ? Thoracic inspiration? 



THE RESPIRATORY APPARATUS AND RESPIRATION. 97 

respiration is most marked in males ; the thoracio, in 
females. 



Fig. 43. 



Fig. 44. 





Fig. 43. A Front View of the Chest and Abdomen in Respiration.— 1, 1, The 
position of the walls of the chest in inspiration. 2, 2, 2, The position of the diaphragm 
in inspiration. .3, 3, The position of the walls of the chest in expiration. 4, 4, 4, The 
position of the diaphragm in expiration. 5, 5, The position of the walls of the abdomen 
in inspiration. 6, G, The position of the abdominal walls in expiration. 

Fig. 44. A Side-View of the Chest and Abdomen in Respiration. — 1, The cavity 
of the chest. 2, The cavity of the abdomen. 3, The line of direction for the diaphragm 
when relaxed in expiration. 4, The line of direction for tlie diaphragm when contracted 
in inspiration. 5, 6, The position of the front walls of the chest and alnlomen in inspim- 
tion. 7, 8, The position of the front walls of the abdomen and chest in expiration. 



171. In respiration, the movements of the ribs are complex. 
Principally by the contraction of the seven upper intercostals 
(152), the sternal ends of the ribs are elevated and carried for- 
ward (Fig. 45). As all the ribs at rest have a downward, slanting 
position, when their sternal ends are elevated the elastic sternum 
and the cartilages are thrust forward and upward, and thus the 
antero-posterior diameter of the chest is increased (Fig. 44). The 

B (jr 9 



98 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



first pair of ribs are fixed. Each succeeding rib is moved, and with 
an increasing amount of movement over the one above it, so that 
there is a transverse enlargement, due to the increase of the sweep 

of the costal arches from 
^iG- 4^- the first to the seventh. 

172. In labored inspira- 
tion additional muscles 
are brought into action. 
The scaleni of the neck 
raise the first and second 
ribs, and the posterior 
superior serrati render 
the four lower pairs of 
ribs more fixed, and thus 
the diaphragm, from its 
insertion, can more easily 
force down the contents 
of the abdomen. In vio- 
lent breathing most of 
the muscles of the chest 
and some of the neck are 
brought into service. 




3 o ^^^^^i 



Fig. 45. 6, Four of the vertebrae, to which are at- 
tached three ribs (7, 7, 7), with their intercostal mus- 
cles (8,8). These ribs, in their natural position, have 
their anterior cartilaginous extremitj- at 4, while the 
posterior extremity is attached to the vertebrse (G), 
which are neither elevated nor depressed in respira- 
tion. 1, 1, and 2, 2, parallel lines, within which the 
ribs lie in their natural position. If the anterior 
extremity of the ribs is elevated from 4 to 5, they 
will not lie within the line 2, 2, but will reach the 
line 3, 3. If two bands extend from 1, 1, to 2, 2, 
they will effectually prevent the elevation of the 
ribs from 4 to 5, as the line 2, 2, cannot be moved to 



173. Inspiration. 
— The enlarging of 
the cubic capacity of 
the chest reduces the 

a, 3. 

pressure of the air in 
the lungs, for the elastic lung expands as the thorax en- 
larges, and hence the air outside rushes in through the 
nostrils or mouth until an equilibrium of pressure is estab- 
lished between the outside air and that in the lung. This 
constitutes inspiration. If a puncture or opening be made 
through the walls of the chest, then will the air, on the 
enlargement of the chest, enter the pleural cavity rather 



173. Describe inspiration. Effect of pleural puncture. 



TPIE RESPIKATORY APPARATUS AND RESPIRATION. 99 

than the lung, and, as a result, the lung will be compressed 
and unable to do its proper duty. Under such a condition, 
the respiratory movements will mostly move the air in the 
pleura. 

174. Expiration. — In normal, easy breathing, expira- 
tion is principally an effect of elastic reaction. By the in- 
spiratory act the elastic portions of the tissues have been 
extended. This stretched condition lasts as long as the 
muscular contraction continues, but, on the cessation of 
the latter, the elastic fibres contracting on the air in the 
lung-tubes drive out a portion of the same, — that is, 
about five hundred cubic centimetres (thirty cubic inches). 
The elasticity of the sternum, the weight of the ribs, and 
the pressure of the abdominal walls acting through the 
contents of the abdomen and the diaphragm, all combining 
cause the capacity of the thorax to be diminished. 

175. A little expenditure of muscular energy may be necessary 
to bring the thorax to its former condition. The internal inter- 
costals, the triangularis sterni, and the abdominal muscles prob- 
ably effect this. In labored respiration the abdominal muscles come 

. into action. In violent expiration all the muscles which can depress 
the ribs or press upon the abdominal contents are forced into 
service. 

176. Diffusion of Gases. — If two gases or vapors, 
of the same or of different density, which do not act chem- 
ically upon each other at common temperatures (like oxy- 
gen and nitrogen, or watery vapor), are placed in the same 
vessel, they will be found, after a certain time, to be uni- 
formly mixed. This is known as diffusion of gases. This 
action of gases is of the greatest importance in the economy 

174. Describe expiration. Amount of air expelled? Aids to ex- 
piration ? 

17G. "What is gas-dilfusion ? Tnlhionoo in nature? 



100 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

of nature. It principally keeps the atmosphere in a uni- 
form state, prevents the accumulation of poisonous gases 
and exhalations in houses and towns, and renders the inter- 
change of gases in the living tissues possible. 

177. Respiration. — The inspiratory and the expiratory 
act taken together constitute a respiration. The fresh air in- 
troduced by inspiration into the upper air-passages contains 
more oxygen and less carbonic acid gas than the air then in 
the small passages. By diffusion the new air gives up some 
of its oxygen to and takes some carbonic acid gas from the 
old air in the tubes, and is then expelled. Hence, respira- 
tion introduces oxygen, a food, into the lung-tubes, and 
removes carbonic acid gas, a waste product, from them. 
By the ebb and flow of the upper air, and the action of 
diffusion between the upper and the lower air, the con- 
tained air in the lungs is being constantly renewed. 

178. When the air enters the bronchial passages it makes 
exchanges with that already there, and, as a result, the 
expired air is warmer, contains much more moisture, is 
about one-fiftieth less in volume, and contains about five 
per cent, less oxygen and four per cent, more carbonic acid 
gas than the inspired air. The expired air also contains 
small amounts of impurities, most of which have a bad 
odor and undergo rapid decay. 

179. Changes in the Blood. — When the dark purple 
blood coming from the right ventricle (124) passes through 
the lung capillaries, it undergoes a change. When it reaches 
the left auricle, it appears of a bright scarlet hue. But now, 

177. What is a respiration ? What is introduced ? What occurs? 
What is expelled? What results ? 

178. Difference between inspired and expired air? 

179. What change in the lung capillaries? In the systemic capil- 
laries ? What is the difference between arterial and venous blood ? 



THE RESPIRATORY APPARATUS AND RESPIRATION. 101 

passing from the left ventricle, and flowing through the 
capillaries of the system at large, it returns to the left 
auricle, having a dark purple color as at first. The prin- 
cipal difference between the scarlet, or arterial, and the 
purple, or venous blood, is in the relative proportions of 
the oxygen and carbonic acid gases contained in each. 
One hundred volumes of blood exhibit about the following 
proportions : 

Oxygen. Carbonic Acid. Nitrogen. 

Arterial blood 20 vols. 39 vols. 1 to 2 vols. 

Venous blood 8 to 12 " 46 " 1 to 2 " 

180. HEMOGLOBIN. — In natural arterial blood but little 
oxygen can be obtained from the serum. The oxygen in 
the blood is found to bear a definite relation to the red 
corpuscles. Haemoglobin is the distinguishing feature of 
red corpuscle, and constitutes ninety per cent, of the dried 
corpuscle (116). When it has lost a part of its loosely 
combined oxygen it becomes of a purple hue. If the 
purple haemoglobin is exposed to oxygen gas, it soon be- 
comes of a scarlet hue. By using oxygen-reducing agents 
and free oxygen properly, this play of colors can be re- 
peated again and again. This adding to and taking away 
from the haemoglobin does not disturb its molecular char- 
acter. 

181. Action of the Corpuscles. — The red corpuscles 
of the blood are oxygen-bearers (123). Its haemoglobin, as 
it passes through the lung capillaries, combines with the 
oxygen, forming oxy-hoemoghbin. This oxygen passes from 
the air-sac, through the walls of the sac and of the capil- 

180. Oxygen in serum ? What of liaMnoglobin ? What of its color- 
olianges ? To what due ? 

181. What occurs in the lung capillaries ? How does it occur ? The 
change in the tissue capillaries ? What of the oxygen ? 

9* 



102 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 




laiy, and through the serum of the blood, to the red cor- 
puscles. When the oxygen-bearing corpuscles in the arte- 
rial stream reach the capillaries of the tissues, a portion of 
the oxygen is left, and a portion of the oxy-hsemoglobin is 
reduced to haemoglobin. Thus the blood becomes venous 
in character. It is believed that the oxygen is stored away, 

in part, in the tissues 
Fig. 46. for future use, and not 

all used in direct com- 
bustion. 

182. Action of 
Oxygen. — The ac- 
tivities of the oxygen 
in the tissues have not 
yet been traced. All 
evidence goes to show 
that the union of the 
oxygen with the elements of the tissues takes place, not in 
the adjoining blood, but in the tissues. Sooner or later it 
appears in combination with carbon and other elements, 
but especially as carbonic acid gas. This latter gas appears 
to be continually formed in the tissues, and as constantly 
to be passed into the capillary blood-current and swept on 
to the lungs, wdiere it is partly expelled into the air-sacs. 

183. The tension of the carbonic acid gas in the air-cells being 
less than that in the capillaries, the latter passes through the capil- 
lary and air-sac walls into the air-sacs. From here, by diffusion 
and the movements of the cilia (164, 74), it reaches the bronchia 
and mingles with the air that is passing out in the movements of 



Fig. 4G. Diagram of a Small Bronchial Tube, 
showing outward aud iuward current produced by 
ciliary cell action. 



182. Where does the oxygen combine ? What is produced? What 
of the product? 

183. What results from over-tension ? The movers in the bronchia ? 
The result? 



TPIE RESPIRATORY APPARATUS AND RESPIRATION. 103 

expiration. Thus one of the great products of tissue-disintegration 
is passed out of the system ; thus the smoke of the myriads of vital 
furnaces is eliminated. 

184. Breathing is an involuntary act. It takes place, 
on an average, eighteen times per minute during the 
waking hours. Although the diaphragm and other inspira- 
tory muscles can be caused to contract more frequently 
by an act of the will, yet these regular contractions occur 
independently of it. Though we lose consciousness, the 
respiratory movements continue at regular intervals. For 
healthy breathing, certain muscles must contract, each at 
its proper moment, each in its proper order. How are these 
movements co-ordinated? By the activity of the nerve- 
cells of the respiratory centre of the medulla (373). 

185. All the brain above the medulla (369) may be removed, yet 
breathing will continue. If the spinal cord be cut through just 
below the medulla, all the chest movements cease, yet the facial 
and laryngeal muscles of respiration continue as before. If the 
medulla be removed, all thoracic, facial, and laryngeal respira- 
tory movements cease. Again, if only a certain small portion of 
this tract be destroyed, all these co-ordinated muscular movements 
cease. After destruction of this centre, death results at once. This 
portion of the cord was formerly known as the " vital knot," but at 
present is termed the " respiratory centred 

186. When one vagus (383) is cut, the breathing becomes slower. 
If both be cut, the breathing becomes very much slower, deeper, 
and fuller. Hence it is evident that impulses arising in the lungs, 
working through the vagi, act on the respiratory centre. If the 
stump of the cut vagi be stimulated, normal respiratory movements 
will occur, but tlioy cease on the removal of (he stimulus. If the 
superior laryngeal branch of the vagi be stimulated, the vagi being- 
uncut, the respiratory movements will be retarded, even stopped. 
The same stimuli, passing over different fibres of the same nerves, 



184. "What of breathing? Inllueiioo of tho will ? Function of the 
respiratory centre ? 



104 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

may cause an acceleration or a retardation of the central action, 
or modify each other's action. Stimuli arising in the cerebrum 
may thus affect the respiratory movements, causing yawning, sigh- 
ing, laughing, etc. ; or the application of cold to the skin will promi- 
nently affect the breathing. 

187. Experiments show that the conditions of the blood affect the 
respiratory centre strongly. The less arterial the blood, the greater 
is the activity of the centre. Thus, under great exertion, or during 
the inhalation of air containing carbonic acid gas, the respiratory 
centre sends out its impulses at an accelerated rate and with in- 
creased power, and the breathing then becomes labored and even 
violent. Under such conditions the impulses may be generated so 
rapidly and sent out so frequently as to exhaust the centre, causing 
cessation of respiration. If, however, the blood becomes too highly 
oxygenated, the centre may remain quiescent [apno&a) until oxygen 
is reduced to the proper amount to excite the impulses due to the 
action of venous blood. The opinion now is that this activity of 
the centre is due to the direct action of the blood upon it. 

188. If an animal breathe an air of carbonic acid gas and nitro- 
gen, the going out of the carbonic acid gas is not impeded, and the 
blood shows no abnormal amount of carbonic acid, yet the animal 
dies with the phenomena of dyspncea, — exaggerated movements, 
labored expiration, violent expiratory movements, general convul- 
sions, exhaustion, long intervals of inspiration, and death. This is 
attributed to the want of oxygen. But if the air breathed, though 
highly charged with carbonic acid, has abundance of oxygen, the 
animal does not suffer from dyspnoea. It, however, becomes drowsy, 
sleepy, and finally unconscious ; that is, the carbonic acid acts on 
the cerebrum as a narcotic, and not on the respiratory centre. In 
brief, the reason the venous blood causes the respiratory centres to 
send out impulses is not the presence of carbonic acid gas in the 
blood, but the deficiency of oxygen. 

189. Pulmonary Statistics. — If we assume that an average 
person, at rest, respires fifteen times per minute, and that at each 
respiration he takes in half a litre (30 cubic inches) of air, then in 
a day he will use 10,800 litres (374 cubic feet) of air. As the air 
in respiration loses 5.4 per cent, of oxygen, the total quantity taken 
up by the lungs in twenty-four hours is equal to 583.2 litres (20.4 
cubic feet), or 833.9 grams in weight (12,867 grains). The amount 



THE RESPIRATORY APPARATUS AND RESPIRATION. 105 

of carbonic acid excreted from the lungs is 4.3 per cent, of the vol- 
ume of the air breathed, and for twenty-four hours is 464.4 litres 
(16.25 cubic feet), or 910 grams (14,043 grains). The amount of 
water carried off in twenty-four hours averages about 255 grams 
(9 ounces). The total daily loss of heat from the body by the lungs 
is estimated at 10.7 calories,^ — 7.2 in evaporating the water of the 
breath, and 3.5 in warming the inspired air. 

190. Oxygen can be taken into the blood not only through the 
lungs, but from the skin and the alimentary canal. The carbonic 
acid passes away from the skin through the various secretions, as 
well as from the lungs. 

HYGIENE. 

191. In order that each tissue and organ shall be able 
to perform its functions properly, the blood must convey 
to them a sufficient supply of oxygen ; that the blood may 
receive its due amount of oxygen, the lungs and air-pas- 
sages must be in good condition, and not impeded in their 
action ; and that the gases entering the system shall not do 
injury, the air offered the lungs must be pure. Not only 
should pure air be supplied to the lungs, but all the impuri- 
ties communicated to the air from lungs, skin, and excre- 
tions should be at once dissipated by the fresh -air dilution 
and air-motion. 

192. Breathe through the nostrils. The hairs at the en- 
trances, acting as a sieve, the structure of the nostrils, of 
the nasal passages, of the uvula, of the oj^en pharynx, and 
the nature of the epithelium (cih'ated) of the mucous mem- 
brane lining the air-portions of these passages, indicate their 

191. What of the oxygen-supply ? Of the air-passages ? Of the 
air? Of air-impurities? 

192. "Why breathe through the nostrils? Objections to brentliing 
through the mouth? 



1 A calorie is as much heat as will niiso tho tomporatm-o of ono l;ilogruni y-l:l ihhuuIs) 
of water 1° C. (1.8° F.). 



106 ANATOMY, PHYSIOLOGY, AND HYGIENE 



respiratory function. In addition, the comparatively long, 
irregular, and tortuous passages of the nose (Fig. 38) en- 
able the entering air to be warmed in passing over the 
extended, highly-vascular surfaces, and to be moistened by 
the copious, thin mucus of the same. Hence the entering 
air on reaching the lung air-passages is moist and of an 
agreeable temperature. Breathing through the mouth is 
noisy, gives rise to bad odors, is unhealthy, and, in cold 
weather, introduces the cold air too quickly to the upper 
air-tubes, chilling their surfaces, deranging the blood-supply 
to the same, and thus giving rise to catarrhs, and perhaps 
to bronchitis and pneumonitis. 

193. Of all the causes of death which usually are in action, 
impurity of air is most important. The chief causes of the 
larger death-rate in the cities over the country are impurity 
of air from overcrowding, want of cleanliness, and imper- 
fect removal of excretions, gaseous, liquid, and solid. The 
evidences of injury to health from impure air are not 
always manifested suddenly and in a marked manner. 
The usual effect is a steady deterioration in health ; an 
increase in the number of sick days per year ; an increase 
in the severity of many diseases unconnected with the 
breathing function, and a higher death-rate, especially 
among the children. 

194. Normal air is a mixture of about twenty-one vol- 
umes of oxygen and seventy-nine of nitrogen, together with 
small amounts of carbonic acid gas, watery vapor, and or- 
ganic matters in either a living or a dead state. The amount 
of carbonic acid is from two to five parts in ten thousand, and 

193. Effect of air-impurity? Cause of large death-rate in cities? 
Effect of continued bad air? 

194. What is normal air ? How much carbonic acid ? How much 
moisture ? 



THE RESPIRATORY APPARATUS AND RESPIRATION. 107 

the watery vapor from forty per cent, of saturation up to com- 
plete saturation, the best for health being estimated at sixty- 
five to seventy per cent, of saturation. The air of an expired 
breath is usually nearly filled with watery vapor. By some 
authorities all organic matter is considered an impurity. 

195. Air-Impurities. — A large number of substances, 
solids, vapors, and gases, continually pass into the air and 
mix witli it, such as that breathed by man and other 
animals, the carbon compounds from fires, lamps, and 
animals, dust, and vegetable decay. Many of these sub- 
stances may be smelt or tasted at first, but soon the senses 
become so blunted that they are not noticed, as when a 
person, coming from the outer air, enters a close room con- 
taining several persons, and detects the bad odors at once, 
but in a short time does not notice the odors, as his senses 
have lost their delicacy. The non-odorous gases, like the 
highly-injurious carbonic oxide, pass unrecognized into the 
air-passages, enter the blood, and work for evil or for good. 
The solid particles entering in the air may stop in the 
mouth, nose, larynx, trachea, giving rise to irritation, 
coughing, or catarrhs, or pass on to the bronchia and finest 
tubes, like the particles of coal in the ^^ miner's lung," or 
the bits of stone in the ^'mason's lung/' or the leather dust 
in tlie " buffer's lung." If these materials remain, they 
cause coughing and expectoration, and may induce disturb- 
ance of nutrition in the parts, giving rise to profuse fetid 
expectorations, formation of cavities, bleeding, and phthisis. 

196. The air of inhabited rooms is rendered impure by the 
carbonic acid comin^: from the lun^s and skin ; the car- 
bonic acid and carbonic oxide coming from lamps and im- 

195, Nanio tbc chief !iir-pt)llutions. How detected? Why not 
detected? What of solid particles? What, are dani;erous trades? 
What diseases follow ? 



108 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

perfect stoves or grates ; the watery vapor from the human 
system ; portions of epithelium from skin, mouth, lungs, 
etc. ; organic gaseous emanations from body excretions and 
from decomposing animal and vegetable materials; par- 
ticles of arsenic from green hangings, and, perhaps, por- 
tions of the dried sputa or secretion from the lungs of 
phthisical persons, or the coutagium of certain skin mala- 
dies. A large amount of carbonic acid in an audience- 
room causes the lamps to burn dimly and the people to 
become drowsy and dull. The carbonic oxide is a rapid 
poison, as it replaces the oxygen in the lungs and is 
not readily removed from them. The watery vapor tends 
to saturate the air with moisture, and thus hinders the 
elimination of certain products (48) from the skin. The 
organic particles contaminate the air, — at one time convey- 
ing disease, at another giving rise to objectionable odors, 
and at all times constituting the most dangerous factor of 
air that has been breathed. 

197. The effects of breathing air rendered hnpure by res- 
piration are quite marked. The common effects are a sense 
of heaviness, headache, inertness, and, in some cases, nausea. 
When the employment is sedentary, and the air moderately 
impure and breathed for hours at a time and day after 
day, then the unfortunates become pale, partially lose their 
appetite, and after a time a decline is seen in muscular 
strength and mental buoyancy. Of the special diseases 
following such conditions of life the lung maladies are 
most common (consumption). When the air is rendered 

196. The impure air of occupied rooms ? "What from the person ? 
Prom the heaters ? Prom the walls ? "What of carbonic oxide ? Of 
moisture ? Of organic matters ? 

197. Early effect of vitiated air in a room ? Later effect ? Special 
diseases ? The poisonous agents ? 



THE EESPIRATORY APPARATUS AND RESPIRATION. 109 

very impure, as in the ^' Black Hole of Calcutta/' or the 
Cooper "Bound Tower/' the effect is rapidly fatal. The 
poisonous agencies are the fetid organic matters and the 
want of oxygen. 

198. In the " Black Hole of Calcutta/' in 1756, one hundred and 
forty-six Englishmen were crammed into a room eighteen feet 
square, having two small windows. During the night one hundred 
and twenty-three perished. After the battle of Austerlitz, ^hree 
hundred Austrian prisoners were confined in a cavern, and in a 
short time two hundred and sixty died. In 1848, the captain of an 
Irish steamer, during a storm, confined one hundred and fifty pas- 
sengers in a small cabin. In the morning seventy were found dead, 
and the others in a wretched state. In 1857, Commander Cooper, of 
the British army, confined two hundred and eighty Sepoy prisoners 
in a round tower. The next morning two hundred and thirty-seven 
were dragged out and butchered, under military orders, the others 
having died during the night from heat, organic emanations, and 
want of air. 

199. Sewer-Gas. — The effects of breathing air rendered 
impure by gases and effluvia from cesspools and sewers are 
languor and loss of appetite, followed by vomiting, diar- 
rhoea, colic, and prostration. When sewer-air continually 
penetrates a house, and especially imperfectly-ventilated 
sleeping-rooms, there arise in children loss of appetite, 
pallor, languor, and even diarrhoea; in adults, headache, 
malaria, and feverishness, followed, perhaps, by typhoid 
fever in its worst form. 

200. The contagious partieles which are at the founda- 
tion of certain dreadful diseases, though often too minute 

'to be detected by the most powerful microscopes or by 



199. Effect of much sewer-gas? Of moderate continued amounts 
on children ? On adults ? 

200. State the effect of contagious particles upon the system. 
"What specific medicine ? JManai^enient in epidemics ? 

10 



no ANATOMY, PHYSIOLOGY, AND HYGIENE. 

the most subtile chemical analysis, are carried about in 
the air or in the clothing, reach an appropriate human 
soil, and make known their presence by their violent ef- 
fects. The germs of typhoid, typhus, and yellow fevers 
and cholera have not yet been isolated. No specific has 
yet been found to render their action harmless. In epi- 
demics, the most powerful agents to be used are free venti- 
lation, pure water, externally and internally, and simple, 
nutritious food. 

201. Contamination of Air. — Air to be used by men 
or animals should not be exposed to sources of contamina- 
tion. All rubbish, all decaying animal and vegetable mat- 
ters, and all excretions, solid or liquid, should be removed 
at once from the vicinity of the houses or stables, for the 
air, in passing over them, cannot avoid becoming tainted. 
To prevent the ascent of bad air from the ground under 
the house and near the house- walls, the cellar should be 
thoroughly under-drained, and, if possible, the bottom and 
sides should be cemented. The waste-pipes — water and 
sewerage — should not connect directly with the sewer 
main. There should be a large air-tube (reaching above 
the roof, at least), as well as a self-acting, efficient trap, out- 
side of the walls of the house, to prevent sewer-gas being 
forced into the house. To prevent disease and discomfort, 
the cellar should be provided with many ventilating win- 
dows, and it ought to be cleaned at frequent and regular 
intervals. "Mould and decaying vegetables in a cellar 
weave shrouds for the upper chambers.'' The cold air for 
the air-chamber of the furnace should not be taken from 
the cellar, but from an air-tight flue coming from the outer 



201. How is outer air mfide impure? Action of cellar-air? Care 
of the cellar ? Of furnace-air ? 



THE RESPIRATORY APPARATUS AND RESPIRATION. Ill 

air, the entrance of which should be three or more feet 
above the surface of the ground. 

202. The Home. — Gravel hillocks are the healthiest of 
all sites, as most natural gravels and sands are healthy. 
Deep vegetable or garden mould, and " made land,^^ es- 
pecially that filled with city and town waste, should be 
avoided, for noxious compounds may be generated in the 
moist, decomposing mass, and, forcing their way into the 
cellar, rise and vitiate the air of the rooms. The sub- 
soil should always be drained, and, if possible, the cellar 
paved. Positions near the top of a slope, on the sunny 
side, are advantageous, on account of the natural drainage 
and the freer circulation of currents of air. The sub- 
soil of all sites should be " pipe-drained.'' The upper 
drain should be so arranged as to remove rapidly all roof, 
surface, and sewage waters. Herbage is healthy, and ought 
to be encouraged near the buildings, as it absorbs and util- 
izes waste organic materials and purifies tlie soil. Trees 
ought not to be recklessly removed, particularly in a new 
country ; yet they should not be left so thick as materially 
to impede the entrance of sunlight and the movements of 
the air. The almost complete extinction of malaria in Eng- 
land, and its decrease in sections of America, have been 
brought about by proper drainage and cultivation of the 
soil, also by the wise preservation and planting of trees. The 
walls of the house ouirht to be so constructed as to insure 
dryness. Building-material ought to be porous, to ])ormit 
free circulation of air. Brick is more porous than lime or 
sand-stone, but less peri\ieablc than })ine wood and mortar. 
If you have an enemy, says an Italian proverb, let him 



202. Mention lioulthy sites. What of ]n-op:\r:ition of ^ito'' Of 
trees? Objects to be secured in buiUiini; a home? 



112 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

occupy your new house the first year of its erection The 
objects sought for in a healthy house are purity and perfect 
cleanliness of air (201), freedom from too abundant moist- 
ure, ample, direct sunlight (60), abundance of pure water 
(227), and quick removal of solid, liquid, and gaseous 
waste products. When these have been obtained, comfort, 
convenience, and adornment may be considered. 

203. Air-Space. — The British army regulations allow 
each healthy man 17 kilolitres (600 cubic feet) of barrack- 
room, and the sick, in hospitals, 34 kilolitres (1200 cubic 
feet). The space allowed for each person in civil life, as 
all are not in health, should be not less than 18.7 kilolitres 
(800 cubic feet), yet 34 kilolitres (1200 cubic feet) would 
be better. The sick should be allowed 34 to 56.6 kilolitres 
(1200 to 2000 cubic feet) space. In addition, arrangements 
are necessary to renew this air frequently, and to renew it 
so as not to give rise to uncomfortable currents. The larger 
the space allowed each person, the less noticeable will be 
the incoming and outgoing currents. The amount of air 
allowed to enter a room should be such that a person enter- 
ing from the outside shall detect no odors and not suflPer 
from the closeness of the room. 

204. Ventilation is the removal, by a current of pure 
air, of the exhalations of the lungs and skin of men and ani- 
mals and the products resulting from the lights of a room. 
Practically, however, impurities from other sources must 
be removed by the air-currents. In summer, the forces 
of nature, diffusion (176) and the action of winds, can be 
relied upon. The former alone is not efficient. Air moving 

203. Malaria. Army air-space. Civil air-space. Why larger air- 
spaces ? Air-currents? Amount of air? 

204. What is ventilation ? What are nature's agents ? Effect of 
heat ? Speak of inlets and outlets for the air. Position of flues. 



THE EESPIRATORY APPARATUS AND RESPIRATION^ 113 

at two miles an hour (almost imperceptible), and allowed 
to pass freely through a space 6.55 metres (20 feet) wide, 
will change the air five hundred and twenty-eight times in 
an hour. In the winter, warming and ventilation must, in 
most houses, work together. If the air of a space or room 
be warmed by persons or by artificial heat, the air expands 
and is forced upward by the in-rush of a similar mass of 
colder and heavier air. This continues until an equilib- 
rium of density and temperature is established. Hence, 
in cold climates, small houses can be efficiently ventilated 
by taking advantage of the currents induced by artificial 
heating. The outlets should be placed near the ceiling, if 
specially warmed outlet-flues are not constructed, and they 
should be slightly larger than the inlets. The inlet tubes 
and passages should be short, and so placed as to be readily 
cleaned. The inlets and outlets should be numerous, but 
not of large size (inlets not larger than 48 square inches, 
outlets, 144 square inches). If the incoming air is not 
warmed, the inlet-tube should open from 1.21 to 2.42 
metres (4 to 8 feet) above the floor. 

205. The open fire is a healthy method of warming a 
room. The heat from it is pure heat, not the drying, 
parching, impure air-warmth of the stove, furnace, or 
steam-pipe. The open fire is, however, more efficient as a 
ventilator than as a warmer. An ordinary fireplace and 
chimney will sufficiently ventilate a room suitable for four 
to six persons, as the outflow is from 170 to 56G kilolitres 
(6000 to 20,000 cubic feet) per hour. If the room is small 
and the fire brisk, the currents of cold air along the floor 
cause the sitter nuich discomfort, which can, however, be 



205. Advantncjos of the open lire? Disadvantagos ? Inthieuoo of 
open fire on hcaltli ? 

A 10^ 



114 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

mitigated by the use of screens. Still, with its minor dis- 
comforts, its tendency to produce draughts, and its expense, 
the open fire is the best method of warming a sitting- or 
sleeping-room. Persons who use an open fire, as a rule, 
are less subject to coughs, colds, headaches, neuralgia, and 
petty bodily ills than those who keep their rooms close and 
warm with stove- or furnace-heat. Rooms warmed by stove 
or furnace can be made more cheerful, more agreeable, and 
more healthy by having a ^' hearth-fire's ruddy glow.'' 

206. Rooms warmed by iron stoves, wood or coal, may 
be fairly ventilated by putting a board about ten centi- 
metres (four inches) wide, and extending from one side of 
the window-frame to the other, under the elevated sash of 
each window ; or by having a wire screen so arranged as 
to follow down the upper sash when it is lowered ; or by 
using double windows, keeping the lower outer and the 
inner upper sash partly open. These methods admit of 
changes of air, yet avoid the making of strong draughts. 
In a sitting- or sleeping-room the stove should have no 
back-damper, in order that the passage of the products of 
combustion to the chimney shall not be impeded in the 
least. As the air of rooms warmed by stoves is too dry, 
water-vessels should be placed near the fire, not on the 
cold, ornamented top, so that the water may be abundantly 
evaporated. The upper sash of all windows should be so 
constructed as to be easily lowered. In kitchens it is ad- 
visable to have a large outlet just over the stove, so that 
the steam and vapors can readily pass away. In cold 
climates, and in most houses, if outlets for the warm air be 
provided, as by lowering the upper sash, cold air will enter 



206. Methods of ventilating common roomo? What of the hack 
damper ? Of the water-urn ? Of kitchen outlet? Of ordinary inlets? 



THE RESPIRATORY APPARATUS AND RESPIRATION. 115 

through defects in carpentry and under the doors and win- 
dows ; but, as such air may flow through an outhouse or an 
impure cellar, it is better to provide clean inlet-tubes, open- 
ing into each room at some distance above the floor. 

207. The sleeping-room^ in which one-third of life is 
passed, ought to be so placed as to receive the direct sun- 
light for several hours each day. Each person ought to be 
allowed 18.7 kilolitres (800 cubic feet) of air-space. If the 
sleeping-room is not provided with a fireplace in which 
there is a fire or light several hours in every twenty-four 
hours, then the upper sash should be kept lowered all the 
time, severe weather alone excepted. These precautions are 
most important, for during the day our senses are active, 
and can so warn us that we may avoid breathing impure 
air, but during sleep, smell and taste do not give us early 
and efficient warning of the presence of impure air, as 
sewer-gas or illuminating-gas, and hence much injury may 
result ere we are warned or awakened. It is best for every 
person to occupy a separate bed. There are many facts 
which go to show that a healthy person, constantly sharing 
a bed with a consumptive, sooner or later contracts the same 
disease, and that when two persons in ordinary health share 
the same bed the influence is not for the best health of 
either. 

208. Consumption. — Persons suffering from disease, 
and especially thoracic disease, need pure air in abundance. 
Pure air is not necessarily cold air, but is air free from all 
mechanical or physiological impurities. The consumptive 
wants not drugs, not stimulants, not medicated pillows, not 



207. Location of sleeping-room ? Size? Ventilation? Why very 
important? Single or double bods ? Why ? 

208. Of air for the sick? Needs of the consumptive? What 
common factor in the }n-oduction of consumption? Remedy? 



116 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



medicated air, but pure air of an agreeable temperature, a 
sun-bath daily in a warm room (the exposure of the surface 
of the body to sunlight), milk, meat, whole wheat bread, 
and fruits (60). The best climates for a consumptive are 
those which permit the greatest number of hours to be 
spent in the oj)en air. The common factor in the causation 
of destructive lung-disease in all climates has been found 



Fig. 47, 



Fig. 48. 




Fig. 47. A Correct Outline of the Venus de' Medici, the beau-ideal of female 
symmetry. 

Fig. 48. An Outline of a Well-Corseted Modern Beauty. 

One has an artificial, insect waist ; the other, a natural waist. One has sloping shoul- 
ders; the shoulders of the other are comparatively elevated, square, and angular. The 
proportion of the corseted female below the waist is also a departure from the symmetry 
of nature. 



to be the breathing of air rendered impure by respiration. 
When the air-space has been enlarged, when the methods 
for the removal of the bad air have been improved (all 
other conditions the same), there has been a marked decrease 
in the death-rate from phthisis in all parts of the world. 



THE RESPIRATORY APPARATUS AND RESPIRATION. 117 

209. Compression of the Thorax and Abdomen. — By wear- 
ing snug-fitting or close-fitting garments, by straps, belts, 
and corsets, the natural movements of the walls of the 



Fio. 49. 



Fto. r,o. 





Fig. 49. A Chest well proportioned. 
Fig. 50. A Chest fashionably deformed. 

chest and abdomen can be impeded. All impediments to 
the enlargement of the cavity of the thorax (169) diminish 
the air-capacity of tlie lungs, hinder the aeration of, and 
excretion fmm, the blood, and thus act injuriously upon 
the entire system. The healthiest mothers in the world 
are the women who do not wilfully impede the movcincnts 
of the walls of the thorax and abdomen by external com- 
pression ; and the healthiest men are those who do not 
bind down their thoracic walls with close-fitting vests and 
coats. The use of the corset is injurious to health, whether 

209. What of compression? Of healthy mothers? Of healthy 
men ? Of the corset? Of Ohlticse vs. Amerioau custom? 



118 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

employed by male or by female. Fashion ordains that 
the Chinese lady shall deform her feet so as to be unable 
to walk, and that the European or American woman shall 
compress her chest and abdomen to such an extent as to 
impede the vital functions of digestion, circulation, and res- 
piration, as well as locomotion. Which civilization, in a 
series of generations, will produce the more vigorous race? 

Individuals may have small chests from birth, this being, to the 
particular individual, natural. That like produces like is a general 
law. If the mother has a small, tapering waist, either hereditary 
or acquired, the form may be impressed on her offspring, thus 
illustrating the truthfulness of Scripture, which declares that the 
sins of the parent shall be visited upon the children unto the third 
and fourth generations. 

The question is often asked. Can the size of the chest and the 
volume of the lungs be increased when they have been once com- 
pressed ? Yes. The means to be used are a full inflation of the 
lungs at each act of respiration, and a judicious exercise of them 
by walking in the open air, reading aloud, singing, sitting erect, 
and practising appropriate gymnastic exercises. Unless these exer- 
cises are systematic and persistent, however, they will not afford the 
beneficial results desired. 

209a. Alcohol, circulating in the blood, lessens the elimination 
of carbonic acid gas by the way of the air passages. It appears to 
interfere with the oxygen-bearing function of the red corpuscles 
by massing them together and preventing ready oxygen inter- 
changes (181). It has not been shown that it increases the oxygen 
osmotic action of the mucous surfaces. It is certain that the ha- 
bitual use of alcoholics in excess (338a) induces marked difficulty 
in breathing and leads to chronic lung disease (emphysema, chronic 
bronchitis, interstitial pneumonia, phthisis). It is not a preventive 
or curative agent in consumption. Many inebriates die of 
phthisis. According to Binz, the peculiar odor of the breath 
after the ingestion of a small dose of alcoholics is not due to ethyl- 
alcohol, but to the ether, fusel oil, etc. in the drink (305a). 



CHAPTER YII. 

FOODS. 

210. In general, plants feed on the carbonic acid gas 
(194) of the atmosphere and a series of chemical com- 
pounds made up of a few elements (C, H, O, N, K, Na, 
Ca, Mg, Fe, S, P, Fl, CI, Si) found in the soil. Under 
the influence of the sunlight the living plant changes these 
soluble (in water) soil-foods and air- foods into plant- tissues, 
cells, and granules. In certain parts of the structures, nota- 
bly the seeds, stems, and roots, plants accumulate a store 
of material fitted to become the food of man or animals, 
such as starch, sugar, fats, and proteids. 

211. The higher animals do not possess the power of 
changing the compounds of the air and soil into animal 
tissues. They feed upon the products of plant-growth, 
directly or indirectly, by eating flesh of other animals, and 
build up the complex animal muscle, fats, starches, and 
proteids, which are suitable for the food of man. 

212. A Food is a substance which, during its destruction 
in the system, gives forth heat or energy (312). Foods 
furnish the materials which build up, repair, and sustain 
the living body. 



210. Food of plants? Influenoo of snnli.t,'ht.? What is stored up? 

211. "What cannot animals do? Foi)d of animals? AVhat is 
made ? 

212. What is a food ? What, in the living body, is derived from 
food ? 

119 



120 ANATOMY, PHYSIOLOGY, AXD HYGIENE. 

213. Foods are of two kinds : 1. Those substances which are capa- 
ble of uniting in the body with oxygen, of giving up oxygen, or of 
splitting up into simpler chemical compounds, and in the process 
manifesting heat, mechanical energy, formative power, etc., and 
thus serving the purposes of healthy life (starches, fats, proteids). 
2. Those substances which aid or permit these manifestations of 
energy by preparing the conditions for chemical changes (water, 
salt, and other mineral compounds). Neither class is of itself alone 
capable of manifesting energy. The full powers of foods are only 
manifested when certain substances belonging to the same class 
exist together. Thus, a proteid alone, like lean meat, wdll not sus- 
tain healthy life, but it must be combined with fats, starches, and 
salts, in certain proportions. 

214. Milk contains all the necessary food-elements, and 
in the best form : 1, the nitr^ogenous or pr^oteid substances 
(C, H, O, N, S, P, Ca), like casein, albumen, etc. ; 2, the 
fats and oils (C, H, O), as in cream ; 3, the sugai^s (C, H, 
O), like lactin ; 4, water (H, O), and the chemic salts 
of magnesium (Mg), calcium (Ca), potassium (K), sodium 
(Na), iron (Fe), in combination with fluorine (Fl), chlorine 
(CI), and the oxygen acids of sulphur (S, O, H), phosphorus 
(P, O, H), and silicon (Si, O, H). 

215. The Proteid or Nitrogenous food-stuffs (C, H, 
O, N, S, P, Ca) are principally derived from the flesh of 
animals, birds, and fishes ; from eggs and milk-cheese ; from 
peas, beans, and vetches ; and from wheat, barley, oat, and 
maize (corn) flours. They are formed exclusively in plants. 
They undergo but little alteration when consumed as food 
and stored up by animals. 

216. T\iQ proteid aliments are blood fibrin, muscle fibrin, vegetable 



214. What does milk contain ? Name its principles. 

215. Sources of proteid foods? By what formed? Changes in 
animals ? 



FOODS. 121 

fibrin, albumen in various forms, vegetable and animal casein, 
and globulin. They contain about sixteen per cent, of nitrogen, 
and usually calcium phosphate. They can replace one another in 
nutrition, but do not have the same nutritive value. 

217. Animal fibrin has a lilamentous structure, and is quite elastic' 
It occurs abundantly in lean meats. Vegetable fibrin occurs as a 
grayish-white, tough, elastic mass. It is found in most plants, and 
is especially abundant in the cereal grains. It is also known as 
gluten. Animal casein occurs most plentifully in milk. It is readily 
coagulated by a solution of rennet from the calf, and thus separated 
from milk, as is seen in the process of cheese-making. Vegetable 
casein, or legmnin, is found chiefly in the seeds of the Leguminosse, 
as in peas and beans. It is precipitated from its juice by rennet 
solutions. Albumen is a white or yellowish-white, transparent sub- 
stance. It occurs abundantly in the fluids of animal bodies and 
in the white of eggs. It is found in nearly all vegetable juices, 
especially in the potato and the wheat. Globulin is a whitish, 
transparent substance. It occurs in the blood-corpuscles and in 
the connective tissues (22). 

218. The Fats and Oils (or hydro-carbons, C, H, O) are 
found in the diet-lists of most peoples, — the fats in the 
cold and temperate, the vegetable oils in the warm regions. 
The fats are principally derived from the blubber of sea- 
animals, from the bodies of animals and birds of the chase 
and of domestication, and from milk. The oils are mostly 
derived from fish, the palm, the olive, the rape, the cocoa- 
nut, and cotton. Maize is rich in oils ; the other grains, 
however, contain only small quantities. 

219. The animal und vegetable ftits and oils are all quite similar 
in chemical composition. They are mostly composed of the base 
called glycerin, united into varying compounds with oleic, palmitic, 
butyric, margaric, and other acids. Their difference in nutritive 
value depends in a great measure upon the physical form, size, 

218. "What are found in tho diot-lists of most nations? Souroos of 
fats ? f oi Is ? Ho w d r i V od ? 

F 11 



122 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

and grouping of the component oil-drops. Some fats, like cream 
and cod-liver oil, are more easily digested, more easily assimilated 
into the blood, than others, like fish or cotton-seed or olive oil, and 
hence have a higher value as foods. 

220. The Starchy class (or carbo-hydrates, C, H, O) 
is a most important part of a normal diet. Its substances 
are mostly derived from the vegetable world and from the 
bulk of the food of the people of the temperate and tropic 
regions. This class embraces the starches of the grains, 
roots, and tubers ; the sugars of the cane, fruits, and milk ; 
the vegetable acid salts (citrates, tartrates, malates, etc.), 
the cellulose of plants, and certain vegetable extractives. 
Chemically, they contain carbon, hydrogen, and oxygen, 
like certain of the oils; but they are physiologically dis- 
tinct from the latter (335). 

221. The Sugars possess a sweet taste, are soluble in water, and, 
undergoing fermentation, form alcohol (241). They are derived 
principally from the cane, the beet, the maple, the fruits, and, to a 
limited extent, from milk. The Starches are principally derived 
from the grains and potatoes of the temperate regions, and the 
marantas (arrow-root), cassavas (tapioca), and palms (sago) of the 
tropics. The starches of the grains are found in the meshes of the 
cellular tissue, which acts as a protective. The starch-grains ap- 
pear to the naked eye as a white, glistening, softish powder. They 
are insoluble in cold water or alcohol. Under the action of direct 
heat, or of boiling, the grains burst, and their contents are more 
easily acted upon by acid and alkaline solutions at the temperature 
of the body : hence the importance of heat-cooking. Human saliva, 
malt, and dilute acids, under conditions of warmth and moisture, 
convert the starch into grape-sugar, or glucose. Cellulose is the 
main constituent of the vegetables, herbs, and greens used by man. 
Chemically it is allied to the starches, but physiologically it is 



220. "What of the starchy or carbo-hydrate class ? "What does it 
inchide ? What resemblance to fats ? 



FOODS. 123 

quite different, in that it affords little or no nutriment. It is useful, 
because its bulk distends the alimentary canal, and thus the diges- 
tive juices can have a greater action on the starches. 

222. The Water and Salts class (H, O, K, Na, Ca, 
Mg, P, S, CI, Fl, C, Si, Fe) has the simplest atomic group- 
iug. It is as essential for healthy nutrition as the proteid 
class. If a normal diet is furnished, all of these constitu- 
ents will be present in sufficient quantities, with the excep- 
tion, perhaps, of common salt (NaCl). 

223. Of the salts, those of potassic and calcic phosphate and sodic 
and potassic chloride are most important. Calcium is absent from 
no tissue. A deficiency of lime salts (calcic) in the foods leads to 
the growth of impaired muscle and nerve and of soft and deformed 
bones (rickets). 

224. Besides the four classes above considered, there are 
substances used by men which may be called Accessory 
Foods. The various condiments, salt, vinegar, spices, rel- 
ishes, etc., tea, coffee, cocoa, and alcohol, are the chief mate- 
rials of this class. Of their exact action in nutrition but 
little is definitely known. It is a general fact that most 
peoples use some one or more of them habitually, in con- 
nection with the other classes of foods. 

225. Diet for Health. — In a cold climate and with 
great exercise, or under severe exposure, a man can keep 
healthy on a diet consisting largely of })roteids, with fats, 
salts, and water. It has not been sliown that liealth can be 
maintained on a diet of proteids, carbo-hydrates, salts, and 



222. The need of the water aiul salts cluss? How provided? The 
exceptions? 

224. Name the chief accessory foods. Their use in imtrition? 
Name a t!;eneral fact. 

225. "What of a diet without starch? Without fat? Without vege- 
table acids? What is scurvy ? Wliat of a perfect diet? 



124 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

water without fat. Health is not sustained on a diet of pro- 
teids, salts, and water, nor on one Avanting in one or more of 
the lactates, citrates, tartrates, nialates, etc., which are found 
in fruits, potatoes, fresh vegetables, and certain preserved 
foods. The want of these is manifested in scurvy^ the 
former scourge of merchant-ships and frontier garrisons. 
The experience of men in all parts of the world, and the 
results of careful experiments, show that a certain amount 
of each of the four classes must be present in a perfect 
diet. 

226. Water enters largely into the constitution of all 
animal tissues. It constitutes sixty-eight per cent, of the 
entire human body. It is the great constituent of meats, 
fresh bread, vegetables, and fruits (233). As a beverage, 
it is one of the most important parts of human food. Good 
water has the following chief characteristics : cleanliness, 
freedom from odor and taste, good aeration, coolness, and a 
certain degree of softness, so that the cooking of vegetables 
can be properly performed. 

227. Good water cannot be derived from an impure source. It 
can be rendered impure by the entrance of impurities into its storage- 
wells, tanks, or pipes. The impurities most deleterious to health 
are human and animal excrements, products of the decay of animal 
and vegetable materials, and lead. The animal and vegetable im- 
purities find easy access to the streams and lakes from which town- 
waters are taken, and to the shallow wells of the country. Many 
sudden and severe outbreaks of cholera, typhoid fever, diarrhoea, 
and dysentery have been traced to the use of water tainted by 
human sewage and cesspool-water. The most efficient artificial 
filtration leaves behind much matter, invisible to the naked eye, 
and is therefore no effective safeguard against these most dangerous 
impurities. The boiling for half an hour of water rendered impure 



226. What of the presence of water in the body ? In foods ? Char- 
acters of good water ? 



FOODS. 125 

by excrement, organic decaying matters, and disease-germs, is prob- 
ably a means of destroying its power of communicating disease. 
The latrine and sewage arrangements of China, Japan, and India 
are very defective, yet the use of boiled water, with a little tea, in 
the former two countries, accounts for the fact that cholera is less 
prevalent in them than in India. The continued use of water having 
traces of lead often induces neuralgic pains, nervous troubles, colic, 
and even " wrist-drop." 

COMPAEATIVE VALUE OF WATERS. 

(I. Mountain springs. ) 
Wholesome. -^ 2. Deep ^vells. | ^^^'^ Palatable. 

b. Upland surface. | Moderately palatable. 

j-4. Stored rain. ) 

Suspicions. 1 5 Surface-water of cultivated land. 

Tliver-water liable to sewage access. 



Dangerous. 

<^7. Shallow well-water, 



Frof. FranMand. 



228. Milk contains all the food-elements needed by the 
body. It is the best food for the young, the convalescent, 
and the aged, because its proportions of fats and proteid 
materials are relatively large, its digestion is easy and 
rapid, and its nutritive power is great in that the residuum 
left in the intestinal canal is small. Milk is best taken in 
the fresh state. Persons who cannot take new milk are 
often able to use milk which has been heated to a tempera- 
ture of 100° F. Its tendency to curdle in the stomach 
may be corrected by the use of lime-water. Its consti- 
pating effects may be corrected by taking it with Seltzer 
water. It should be derived from healthy cows which are 
kept under favorable conditions of air, water, and food. 

229. One pint (.508 litre) of the milk of the cow contains in 
round numbers nearly 55.(5 grammes (2 ounces avt)ir.) of wntor-lVee 
food. An adult man requires for the average manifestation of his 
working powei-s 050 grams (28 ounces) of water-free food in twenty- 

228. Milk as }i food ? Motlunls of using ? Precautions? Quality? 



126 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

four hours. To procure this from cow's milk would require the 
consumption of about 6.2 litres (11 pints). This would give a man 
far too much water, and the fats would be in excess of a normal 
diet (338). 

230. Cooking. — The use of fire in the preparation of 
food is peculiar to man. Its use, whether direct, as in 
roasting, baking, and broiling, or indirect, through the 
agency of water in boiling or of fat in frying, changes the 
physical and chemical condition of the cooked substances : 
the proteid bodies are more or less coagulatecl or partly 
swollen or gelatinized ; the fat-cells are ruptured, and the 
fats rendered more fluid ; the starch-grains become more or 
less pulpy; the cellulose and the lignin of vegetable tissues 
are more or less broken up, and their contents set free; 
and peculiar empyreumatic flavors and odors are devel- 
oped. The foods are thus rendered softer and more finely 
divided, and hence can be more readily masticated and 
digested. By the use of sugar, salt, spices, vinegar, etc., 
the relish of the food is increased. 

231. Methods of Cooking. — Animal flesh (oysters 
excepted) and starchy and cellulose substances (certain ripe 
fruits excepted) should be cooked before eating. The sim- 
plest methods of cooking make the most* healthful food. 
Boiling^ in the case of vegetables, effects the solution of 
the sugars, the rupture and partial solution of the starch- 
grains, the coagulation of the proteids, and a softening of 
the cellulose. In boiling meats, first plunge the meat into 
boiling-hot water, and retain it there until a protective layer 
of coagulated albumen forms on the surface. This requires 

230. What food-preparation is peculiar to man ? Methods of cook- 
ing? Effects? Use of condiments? 

231 . What should be cooked ? Boiling of vegetables ? Of meats ? 
Of wasting of meats? Of vegetables? Objections to frying? 



FOODS. 127 

a few minutes only ; then cook slowly in water having a 
temperature of 160° F. This method retains in the meat 
most of the soluble nutritive portions. Roasting and broil- 
ing are the best methods of cooking meats. The heat at 
first should be intense, in order to form a protective layer 
to retain the juices, and then more moderate, but long con- 
tinued. By this method but little is wasted, and more 
nutrient materials are retained than by other methods of 
cooking. The roasting of fruits and potatoes renders them 
more palatable, digestible, and nutritious. The baking of 
flour renders it sweeter, breaks the starch-grains, and makes 
it more digestible. Frying is the most objectionable method 
of cooking, for the heated fats permeate the foods and render 
them difficult of access to the digestive fluids. 

232. Meats. — The advantages of these food-substances are the 
large amounts of proteids, united with much fat, and the presence 
of the salts of potassic chloride, phosphate, and carbonate, and iron. 
They are easily and rapidly cooked, are more easily digested than 
vegetables, and are very largely assimilated (236). Meats are, how- 
ever, wanting in the starches, and are therefore well supplemented 
with rice or bread. Salt meats, as far as nutrition is concerned, are 
but little better than meat from which a good soup has been ex- 
tracted. Canned meats are excellent when fresh meat is not to be 
had. The eating of raw or partly-cooked flesh or fish exposes 
the system to dangers. Fresh pig's flesh may contain the trichinre 
or the cysticercus of the tape-worm ( Tmnia solium) ; fresh ox flesh, 
the cysticercus of the tape-worm [T. medlo-canclhita) ; and fish, the 
eggs of intestinal worms. The eggs and the immature worms found 
in the flesh are not destroyed by a temperature luider 212° F. : hence 
prolonged roasting is the best method of cooking flesh. Eygs are 
easily cooked, and are very nutritious, nard-boiled and fried egg's 
are more diflicult of digestion tluui soft-boiled and whipped egg's. 
Fish is well adapted to su{>plement cereal foods, and is used most 
extensively in rice-countries. It is rich in phosphates and pro- 
teids, and the latter occur in a form easily appropriated by the 
human system. INIany kinds of llsh are dollcient in fats. 



128 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



TABLE OF COMPARATIVE FOOD-VALUE.i 



Medium beef 100 

Fresh milk 23.8 

Skimmed milk 18.5 

Butter 124 

Cheese 155 

Hens' eggs 72 



Fresh cod 68 

Eel 95 

Shad 99 

White-fish 103 

Salmon 104 

Salt mackerel Ill 

Prof. Atwaier. 



233, Wheat is very nutritious in small bulk, and is rich in soluble 
albumen and casein. Its starchy substances are large in amount 
and are easily digested. Its salts are principally phosphates. The 
fine flour made from wheat is wanting in fate, salts, and part of 
the albumen. Decorticated wheat flour contains all these ingredi- 
ents, and is a more healthful food than finely-bolted flour. Bread, 
pudding, etc., made from decorticated wheat flour are sweeter, 
more nutritious, and more wholesome than those made from fine 
white flour. Barley contains a larger amount of digestible proteids 
than wheat. It is very rich in phosphates and iron, and is a nutri- 
tious food-stuff. The athletes of ancient Greece were trained on a 
barley diet. The oat has not only a large amount of proteids, but 
also is rich in fat. Though it cannot be made into bread, yet it is 
more readily cooked than wheat or barley. It makes an excellent 
food for sustained mental or physical labor. Oatmeal, made into 
the form of a thin gruel, forms a most sustaining and cooling drink 
for men exposed to great heat (as the stokers on the Oriental 
steamers, and soldiers in hot countries). Cracked wheat, oatmeal, 
and milk should occupy a prominent place in a student's diet. Maize 
contains a large quantity of yellowish fat. It is an excellent food- 
stuff" for hard labor and for cold climates. It requires longer and 
more carefiil cooking than wheat or oats. Rice, as an article of 
diet, has the advantage of being the most easily digested and the 
most perfectly assimilated of the starch-grains. It is poor in fats 
and salts. The Japanese rice is the richest in gluten of any pro- 
duced in the East. Rice is four times as nutritious as potato 
(Konig), and is also more uniform in quality. It constitutes the 
great food of nearly one-third of the human race. The potato has 
a very low nutritive rank, although ite starch is very digestible. 
It contains the citrates of soda, potassa, and lime. It is the great 
antiscorbutic vegetable, and constitutes a food of which man rarely 

1 Equal weights, no bone. 



FOODS. 



129 



tires (225). Beans and^eas are distinguished from other vegetables 
by containing a large amount of proteid substances, principally in 
the form of legumin, a vegetable casein. They contain much sul- 
phur and phosphorus. They make an excellent food for men with 
robust digestion engaged in severe labor. In the rice-countries, 
beans and peas are largely used. Their disadvantage is the long 
cooking which they demand, and their comparatively great indi- 
gestibility. 



ORDER 


OF RICHNESS IN 


THE UNCOOKED 


STATE. 


Proteid sub- 
stances. 


Fats. 


Starch carbo- 
hydrates. 


Mineral salts. 


Beans. 


Maize. 


Rice. 


Beans. 


Peas. 


Oats. 


Rye. 


Oats. 


Wlieat. 


Barley. 


Maize. 


Peafi. 


Oats. 


Peas. 


Wheat. 


Wheat. 


Rye. 


Rye. 


Barley. 


Barley. 


Maize. 


Beans. 


Oats. 


Maize. 


Barley. 


Wheat. 


Peas. 


Rye. 


Rice. 


Rice. 


Beans. 


Rice. 



ArnaHjed froiii uuali/sis of Profs. Wolff and Kno]}. 

234. Fruits are most valuable for their vegetable acid salts and 
watery constituents. Their solid nutriment is small. A moderate 
amount of ripe fruits in their season is beneficial. Unripe fruits 
contain starch which has not yet been converted into sugar. Cook- 
ing often removes the hygienic objections to the use of unripe fruit. 
Eather than use sugar in excess to neutralize the acidity, add about 
one-eighth of a teaspoonful of carbonate of soda, or potassa, to a 
pound of fruit. 

235. DiGESTiRiTJTY. — Flfciiess for digestion depends 
partly on the hardness, cx)liesion, or chemical nature of tlie 
food, and partly on the changes it may luive undergone in 
passing through the system of a food-animal or under the 
processes of prej)aration and cooking. A pound of bread 
contains more solid nutritive matter than a pound of beef- 
steak ; but, with an ordinary man, it does not do as much 



235. Upon what, drpoiuls {ho aigostibility of food ? Of broad? Of 
beefsteak ? Of salmon ? Of choose ? 



130 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

nutritive work, because the cooked meat is more digestible 
and is more completely assimilated than the bread. The 
same is true of equal weights of salmon and cheese, of 
venison and lean pork. 

Cooked rice, cooked tripe, Mhipped eggs, cooked sago, tapioca, barley, boiled milk, raw 
eggs, roasted lamb, i)arsnips, and potatoes are the most readily digested of foods, and in 
the order given. Cooked in the most favorable manner, beef, mutton, oysters, veal, fowl, 
and white wheat-bread, with butter, are rather less digestible. Fresh pork, salt pork, 
and salt beef require still more time and energy for digestion. 

236. As a rule, animal food is digested sooner than 
starchy food, and in proportion to its fineness of division 
and its tenderness of fibre. The admixture of the differ- 
ent classes of foods, as of fat and lean meats with starchy 
and accessory foods, aids digestion. We should seek for 
variety in foods of the same class, as of beef, mutton, eggs, 
fish, etc. ; beans, peas, cereal grains ; rice and potatoes. As 
sameness cloys, changes in the combinations of the food are 
essential. Cooking requires skill, which in reality assumes 
the importance of no inferior art. 

TABLE OF DIGESTIBILITY. 

{Giving the Percentage which is incorporated into the Human Body and the Percentage lohich 

is rejected.) 
Incorporated. Residuum. 

Meat 96.7 3.3 

Rice 96.1 3.9 

Eggs 94.8 5.2 

White bread . . . 94.4 5.6 

237. Stimulants.— A stimulant has the power of exciting the 
organic action of the human body. It calls forth the stored-up 
forces of the system, and enables them to be used at once. It 
goads the system on to an increased exertion, mental or physical, 
and thus enables a person to draw on the reserves of his vital bank. 
When the deficit in the reserves is promptly made up by rest and 
appropriate nourishing foods, the vital bank appears to suffer no 

236. Advantages of animal food ? Of variety in foods ? The art 
of cookins: well? 





Incorporated. 


Residuum 


Maize . . . 


. . 93.3 


6.7 


Potatoes . . 


. . 90.7 


9.3 


Milk . . . 


. . 88.9 


11.1 


Black bread . 


. . 88.5 


11.5 
Piof. Voit. 



FOODS. 131 

physiological impairment ; but if the deficit steadily increases, then 
mental and physical bankruptcy will result after a longer or shorter 
period. The principal stimulants in use are tea, cofiee, cocoa, and 
alcohol (407, 408, etc.). 

238. Tea is used by peoples whose food consists largely of carbo- 
hydrates, like the Chinese and Japanese. Its active principle, thein, 
gives to food something which it did not before contain. Tea seems 
to enable persons to do work on a smaller diet than would otherwise 
be required. It has the power of putting away sleep, and it enables 
a person to draw on the stored-up resources of the body for an 
increased exertion. It is thus largely used by the under-fed and 
overworked seamstresses of the large cities. The action of the thein, 
combined with the warmth of the infusion, braces up the nervous 
system, but no marked depression follows. It is a stimulant, but 
not an intoxicant. The hot infusion is potent against cold and heat 
(inducing perspiration), and is useful under great fatigue in hot 
countries. Tea, as made in America, should not be used by chil- 
dren. The excessive use of strong-made tea leads to nervousness^ 
neuralgia, and indigestion. 

239. Coffee makes a pleasant, stimulant beverage. It removes 
the sense of commencing fatigue during exercise. It is very ser- 
viceable against cold. In the British Antarctic Expedition it was 
found superior to spirits. According to the Algerian and Indian 
army reports, it has been found well adapted to keep up the men 
in a campaign under a tropic sun, in that it affords an invigorating 
nervous stimulation and increases the action of the skin. Coffee 
does not give rise to the nervous symptoms which follow the exces- 
sive use of tea. It should, however, be excluded from the diet of 
chiklren and of youth of both sexes, on account of its peculiar 
stimulant action. It is said that in Brazil, where coffee is largely 
drunk by all classes, alcoholism (408) is almost unknown. 

240. Cocoa contains a large amount of fat and proteid substances. 
It has been compared to milk, but it is inferior as a food. It may 
profitably be substituted for tea and coffee by persons of a spare 
habit. It is a valuable drink for adults under circumstances re- 
quiring great exertion. 

241. Alcohol (ethyl-alrohol, CJT^.O) is mado (Vom 
sugar by feiMnoiitiition, or from staivhos which liavo boon 



132 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

changed into sugar. The grains, fruits, grapes, and potato 
are the principal source of the starches so used. Pure alco- 
hol is a colorless, limpid fluid. It is lighter than water, and 
has a pungent, agreeable taste and odor. Spirits, wines, and 
beers owe their stimulating and intoxicating properties to 
the alcohol they contain. The amount of alcohol in them 
varies from 1.28 per cent, in small beer to 54.32 per cent, 
in Scotch whiskey. 

242. There is a wide-spread consumption of alcohol in 
the world. All civilizations have their means of acting on 
the nervous centres, — of transporting their people into a 
more exalted condition of mental activity and physical 
buoyancy, the excessive and evil manifestations of which 
are called intoxication. From the drinks made by the 
women of the Polynesian islands by chewing pepper and 
spitting the profuse saliva into a bowl (the contents of 
which are drunk by the warriors), the pulque of Mexico, the 
talluh of Abyssinia, the koumis, sake, and arrack of Asia, to 
the vodki, spirits, wines, and beers of Europe and America, 
— everywhere man has devised stimulants and intoxicants. 
The more civilized a nation becomes, the greater appears 
to be the variety of its alcoholic beverages. This craving 
for stimulants is not only world-wide, but there are reasons 
for believing that it is on the increase. Where the use of 
alcohol has been restricted, it has been found that the con- 
sumption of other stimulants, like opium, ether, tea, and 
coifee, has vastly increased. 

243. Action of Alcohol. — Alcohol is a carbo-hydrate. 
Taken into the system in small quantities, it is destroyed in 



241, The sources of alcohol? Characteristics? Percentage in 
beverages ? 

242, Of the use of alcoholics? The action desired? Kinds of 
drinks? Of the craving? Of the use of other stimulants? 



FOODS. 133 

the body, and generates force and heat. It restricts tissue- 
waste, and in some cases favors the accumulation of flabby 
adipose tissue. Alcohol decreases the elimination of car- 
bonic acid and the excretion of urea. It thus tends to re- 
tain these waste products in the blood (324). It quickens 
the functions of the organs of circulation (147), and modi- 
fies the nerve-centre control (paralysis). In small doses, it 
aids feeble digestion ; in large doses, long continued (espe- 
cially undiluted spirits), it ruins the digestive function. 
Alcohol induces a marked disease-process in the liver and 
kidneys. The continued use of alcoholics probably in- 
duces an abnormal condition in all the soft tissues of the 
body, as shown by the hues, textures, and functions 
(408). Cell-softening is often noticed, also cell-hardening 
as in the fibrotic-changes evident in the " gin-drinkers^ 
liver,'' in the "alcoholic-contracted kidneys" (305), and in 
the thickened leathery walls of the stomach. The alcohol 
not consumed in the system is eliminated by the kidneys, 
skin, and lungs {Q7 a, 87 a, 209 a, 270, 290, 338 a, 407). 

244. Alcoholics, occasionally and judiciously used, enable 
a person to employ his reserves of force by setting free body- 
energy not called out by ordinary nerve-cell action. There 
are conditions — not quite diseased conditions — which are 
improved by the temporary use of a little alcohol. After 
exposure and great exertion, the shelter having been 
reached, a small amount of alcohol or spirits in hot water 
is often beneficial. Selected spirits, at times, are useful 
additions to the food of invalids, but should be taken with 



243. Give tho action of mIcoIioI. AVhat olVccl on the waste products 
of the system ? On dig-estion ? On all tho soft tissues ? How shown ? 
How eliminated ? 

244. Uses of alcoholics ? Docs takini;' alcohol jn-event contracting 
disease ? 

12 



134 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

the food, and not alone. The abstemious derive the best 
eflPect when a dose of alcohol is administered. As a rule, 
alcoholics should never be used except for a specific pur- 
pose and under the continued advice of a physician of 
integrity. Alcohol is not a preventive of disease, but the 
reverse. 

245. Alcohol is injurious to the young or immature of 
either sex. Its evil effects are more marked in females 
than in males. In hot climates it is a fertile source of 
disease, and has no compensating advantage. Before or 
during severe exertion, or before or during exposure to 
low temperatures, alcohol ought not to be taken. The 
Russians will not permit a man who has recently indulged 
in the use of spirituous liquors to undertake a cold march. 
In health, alcohol is not a necessity, and the majority would 
be more vigorous did they not use it in any form. As 
now used by mankind, it is more powerful for evil than 
for good. It is a ^^ genius of degeneration,'^ moral, mental, 
and physical (408). Its baneful influence is not confined 
to the generation that uses it, but the deterioration induced 
on the nervous system has a peculiar tendency to hereditary 
transmission. Insanity, idiocy, instability of mind, weak- 
ness of will, and a craving for alcoholics occur more fre- 
quently in the offspring of the habitually intemperate than 
in those of water-drinkers (401). 

245. To whom, in particular, is alcohol injurious ? In hot climates ? 
In cold climates? What is said of the Russians? Influence on this 
generation ? On succeeding generations ? Results ? 



CHAPTER YIII. 

THE DIGESTIVE ORGANS AND DIGESTION. 

Directions for Dissection of Abdomen. 

Secure the animal (preferably a dog or cat; a rat may be used) on its back by means 
of blocks. Make an incision through the skin from the sternum to the pubes. From 
near the nmbiliciis (navel) make two incisions at right angles to the first, extending 
nearly to the luiuhar verlehral processes. Fasten back the skin after it has been dissected 
from the underlying muscles. Observe the pale uhdoudnal muscles; the glistening fascia 
of the muscles, forming in the middle line the linea alia; the fibres of the external oblique 
inuscle. Cut the fascia near the median line of the body, elevate the fascia, and expose 
the rectus muscle. Dissect off the external oblique muscle, and expose the internal ohlique 
muscle, having fibi-es running in a different direction from the external. 

With scissors, divide in the median line the walls. A large cavity, lined by a smooth 
moist membrane, the peritoneum, is exposed. This membrane lines the abdominal cavity, 
and is reflected over the intestines and organs contained therein, and serves to keep the 
latter in their proper places. Without cutting or tearing, but by simply turning over or 
pulling aside, trace the ulimenlury canal from near the left inferior side of the diaphragm, 
viz., the narrow oesophagus, the dilated stomach, the convoluted small intestine, the large, 
dark, sacculated cwcum, with its worm-like appendix, the large intestine, containing balls 
of excrement, and the rectum. Trace out the mesentenj, made of two folds of the peri- 
toneum, enclosing blood-vessels, lymphatics, and nerves, which connect the alimentary 
canal to the vertebral region. If the dog is in good condition, a loose, mesenteric, fatty 
apron, the yrcal omentum, will be seen hanging from the lower border of the stomach. 
Notice the dark-purple-colored long body lying near the broad end of the stomach, the 
spleen. Observe the form, the lobes, the tiibcs entering, and the attachments of the large, 
dark-red solid organ, the liver. Now turn ovisr the stomach, slightly stretch the small 
intestine, and notice within the mesentery the long, hammer-like, pale-red, k)batod pan- 
creas. Trace the duct from the pancreas to its entrance into the small intestine, about a 
foot from the stomach. 

Turn the stomach and intestines to the right side (towards the liver side of the anini:il). 
Notice the abdominal aorta at its exit from the diaphragm. Follow its branches to the 
piin(MpaI organs. On the surface of the «>soi)hiigus may be seen a few fibres of the pncn- 
moijastric ncrrc. Turn the stomach and intestines to the leftside. Trace the llaceid tubed 
(containing dark maroon blood) from the mesentery, spleen, and stomach until they unite 
in a single trunk, the portal vein, which is seen to enter the liver. Observe the rcna cara 
uscendens as it enters the diaphragm, receiving blood froni the liver. Turn the dark-rod 
liver up towards the diaphragm, and its greenish ;;((//-?»/(((/(/<r, with its ci/stic duct, and the 
hepatic duct (from the liver), forming one commott duct, will be brouglit into view. 

Place a double ligature around the rectum, and liivide betweiMi the exrds Put a sini;lo 
ligature on the hepatic veins, close to tl\eir entrance to tiie vena cava, and divide close 

18o 



136 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



Fig. 51. 




The Digestive Organs. 



THE DIGESTIVE OEGANS AND DIGESTION. 137 

to the liver. Put a ligature on the oesophagus, and divide on the thoracic side of the 
same. Eemove tlie alimentary canal and its appendages by cutting the mesentery free 
from the posterior walls of the abdomen, then carefully trim the mesentery from the 
alimentary canal. Examine the tube externally from the stomach to the rectum. 

Sever the stomach from the intestines, lay open, throw away the contents, and wash. 
Place it in a shallow basin of water, the interior upward, and observe the structure of 
the fining mucous membrane. Treat portions of the intestines later in the same way. 
Attach the alimentary canal to a water-tap, and wash out the interior. Pass bristles 
through the pancreatic and biliary ducts. Lay open the duodenum (the upper portion of 
the small intestines), find the bristles, and study the mucous membrane. Lay open the 
next five or six feet of intestine, wash, spread out in a shallow basin of water. Notice, 
with a lens, the projecting, velvety villi. Cut out a portion of the large intestine, treat 
in the same way, but no villi are to be found. 

Cut open the liver. Trace a hepatic vein from the vena cava into the substance of a lobe. 
Try to distinguish the portal vein from the hepatic vein by the small artery and duct run- 
ning alongside the former. Cut open the spleen. Note its fibrous investment, its pulpy 
contents, and the absence of a duct. Separate the long, pale-red p)ancreas, and note ita 
friable, lobulated character. Observe to the right and left of the backbone a compact, 
roundish, solid organ, invested by areolar, tissue-holding fat, the Icidneij. Note that the 
left kidney is nearer the pelvis than the right. Trace from the backbone the renal artery 
and vein leading to and from the kidneys. Notice the ureter, a pale, firm-feeling duct, 
running from a depression in the kidney towards the middle line into the pelvis, and 
ending in the bladder. Note the soft body capping the kidney, the suprarenal body. Tear 
the kidney out of its sheath, dissect the ureter, artery, and vein about an inch, then cut 
away the kidney. Lay open the kidney by a longitudinal incision parallel to the flat side. 
Note the dilated ureter, the yelois of the kidney, the projecting pajj/fe, the incised j^^/j-a- 
mids, the medullary substance, and the cortical layer (see Fig. G9). 

Divide the pubes, and stretch open the pelvis. Lay open the bladder. Within and 
near the pelvis are the organs of generation. 

Microscopic Work. — Cut out cubes of the various organs and place in No. 1 alcohol. 
Later make sections. 



THE ALIMENTARY CANAL AND ITS APPENDAGES. 

246. The Abdomen.— The essential or2:ans of diVestion 
occupy nearly the whole of the abdomen (Figs. 51, 34, 23). 
The abdomen is walled in by broad nuiscles, fasciie, and 
skin, except behind, where the projecting processes and tlie 
bodies of the five lumbar vertebriv assist (Fig. 49), above 
by the vaulted diaphragm, and below by the bones of the 
pelvis, tlie cavity formed by the latter being siii)plcmentary 
to the abdomen. The capacity of tlie abdomen varies, 

246. Where are the chief organs of digiest.ion found? Bouiularies 
of the abdomen ? The pelvis ? The peritoneum ? 



138 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



owing to the Dature of its walls. It is lined by a closed 
serous sac (156), the 'peritoneum j whose visceral layer is 
reflected over the contained viscera, forming the thin exter- 
nal sei'ous coat. 

247. The Bony Pelvis is composed of four bones, — 
the two innominata, which bound it on each side and in 
front, and the sacrum and coccyx, which complete it be- 

Fia. 52. 




Fig. 52. Front View of the Pelvis. — 1, 1, The innominata. 2, The sacrum. 3, The 
coccyx. 4, 4, Socket, e, The junction of the sacrum and lower lumbar vertebra. 

hind. It is a strong and massive ring of bones placed 
between the lower end of the spine, which it supports, and 
the lower extremities, on which it rests. Its position, in- 
clined to the spine in standing, enables it to sustain the 
superincumbent viscera. Its large and projecting surfaces 
are used for muscular attachments, and they aiford lever- 
age for those muscles which pass upward from the lower 
limbs, serving to balance the pelvis upon the thighs (Fig. 
128). The sides and base of the cavity are completed by 



247. The bones? Form? Position? Attachments? Object? Con- 
tents ? 



THE DIGESTIVE ORGANS AND DIGESTION. 139 

muscles and fasciae. It holds the rectum and bladder and 
some of the organs of generation. 

248. The Digestive Apparatus consists of a mech- 
anism for dividing and crushing the food (in the mouth), 
of a long musculo-membranous passage, variable in size, 
lined with mucous membrane, and extending from the base 
of the skull to the end of the rectum, called the alimentary 
canal, and of certain accessory organs called glands. 

249. The Alimentary Canal, lying in the neck, in 
front of the spine, passes through the thoracic cavity (148), 
perforates the diaphragm, and runs a tortuous course 
through the abdomen and a straight course in the pelvis. 
It is about thirty feet long, and has variable diameters. It 
embraces the mouth, pharynx, oesophagus, stomach, small 
intestine, and large intesthie. Its lining mucous membrane 
(165) is modified in each region according to the functions 
of the part, and is continuous at both extremities with the 
skin. Its muscular fibres are mostly of the unstriped 
variety (72), and are arranged lengthwise and circularly in 
the tubular portions. Its layers — serous, muscular, areolar, 
and mucous — are abundantly supplied with blood-vessels. 
The tube has nerve-ganglia (345), and receives fibres from 
the central and sympathetic systems (386). In the abdo- 
men the tube has much freedom of motion, owing to its 
mesenteric attachments (264). 

250. A Gland (1.GG) is a term applied to tliose softisli, more 
or less granular and lobated organs composed of blood-vessels, 
nerves, areolar tissue, and secreting tissues. The latter tissues 
are epithelial in nature, being in most positions modiiied mucous 
membrane. The function of these tissues is to take blood into 



248. Of the composition of the digestive apparatus? 
240. Position of the alimentary canal ? Length? Parts? Lining 
Coats? Movement? 



140 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

their structures, to build up themselves, and out of or through 
their protoplasm to produce materials, usually fluid, different in 
properties from the blood, or to secrete and modify from it sub- 
stances already there in solution (275). Such organs are provided 
with ducts or tubes, to convey away the gland-products, as the pan- 
creatic duct, Steno's duct of the parotid. Certain of the glands have 
sacs or pouches, in which the secretion collects, like the gall-bladder 
of the liver. 

251. The Mouth (Fig. 38) is bounded by the lips in 
front and the soft palate and arches behind ; above, by the 
hard palate ; below, by soft structures ; and on the sides, by 
the cheeks. It is lined by mucous membrane. It contains 
the tongue and teeth. Wlien shut, the cavity is completely 
filled. It is the main entrance to the alimentary canal, and, 
vi^ith its appendages, is of great service in speech. The 
Tongue is made up of many muscles and considerable fat. 
Its apex, sides, upper surface, and lower front part are 
free. Its muscles are attached to the hyoid bone and the 
lower javj principally. Its upper surface is covered by 
peculiarly developed papillae or eminences. It contains 
the nerves which are chiefly concerned with the sense of 
taste (427). Into the mouth open the ducts from three 
pairs of glands, and upon its lining surfaces is discliarged 
much mucus. 

Directions for Examination of the Mouth Parts. — Request a boy having a good set 
of teeth to stand before the class. Call attention to the lips: line of junction of skin and 
mucous membrane, contour, angle of junction, mobility. Dental arch: upper and lower 
jaw, — form of arch, insertion of teeth, the gums, order of teeth from the median line, — 
incisors, ccaiiiies, hicuspich, and molars; variations in the cutting surfaces; of the grinding 
surfaces; points of decay. 3Ioveme)ils of the lower jaw : forward, backward, to the riglit 
or left, and combinations of movements. While cutting a firm object, feel the masseter 
muscle ami the angle of the jaw. Place the finger in front of the ear, over the jaw 
articulations, then move the jaw slightly, then stretch open ; notice tlie degree of motion. 
Hard palate : notice its hard surfaces, with ridges, the soft posterior portion terminating 

251. Limits of the mouth ? Contents? Functions? The tongue? 
Muscles? Papillae? Taste? Ducts? 



THE DIGESTIVE ORGANS AND DIGESTION. 



141 



In the soft palate, or uvula. Tongue : its free apex, its bridle, its veins prominent on 
the lower surface. On its upper surface note the numerous minute, conical filiform 
papillse, the irregularly scattered, large, round eminences, liaving a deep red color, the 
futigiform paplllse, and near the posterior part, arranged in a V shape, eight or ten flat- 
tened circumvuUale papillie. Observe the- variety of movements which the tongue can 
execute. Throat: Request the boy to stand in the siinligflt, mouth wide open, head 
slightly thrown back, and then to articulate slowly, Ah~ah — h — h. Thus the soft palate 
will be elevated, the palatine arches widened, and the throat parts brought into view ; 
the soft palate in the middle line, over the dorsum of the tongue, the right and left 
anterior parts; behind them the right and left almond-shaped tonsils, then the posterior 
2)illars and the posterior wall of the pharynx in the central field. Observe that the mouth 
and pharynx are lined with mucous membrane, and that the surfaces are bathed with 
mucus. If the mouth is suddenly opened, a jet of fluid may come from near the second 
upper molar tooth,— saliva from the duct of Steno (parotid), or, if the tongue is raised, 
from the floor,— saliva from Whurtou''s ducts. Wipe the mouth and tongue. Hold a bit 
of cracker. Remove. Move the mouth parts a few minutes, and then insert a new bit 
of cracker and hold a few moments. What changes have taken place in each case ? 



252. The Upper Jaw consists of two bones, meeting in the 
middle line, called the superior maxillce (Fig. 73, 7). Each half 
in the adult contains sockets 



for eight teeth. The hard 
-palate is mostly formed of the 
lower portions of these bones 
joined in the median line. 
These bones are firmly at- 
tached to the adjacent bones 
of the face. The lower jaw, or 
inferior ynaxilla, is the only 
movable bone of the face. It 
consists of a horseshoe-shaped 
base, having two nearly ver- 
tical rami, ending in a process 
and an articulation. The upper 
surface of the base offers six- 
teen sockets for teeth. This 
bone forms a hinge-like joint 
with the tenii)()ral bone (Fig. 
73, 9). By the action of cer- 
tain muscles the bone may be 
moved up and down, forward ; 
tions of these movements. 



Fig. 58. 




Fig. 53. 1, The body of the lower jaw. 2, 
Ramus, or branch of the jaw, to which the 
muscles that move it are attached. 3, 3, The 
processes which unite the lower jaw with the 
head, i, The lower and lateral incisor teeth 
of one side. /., Tlie bicuspid teeth. <■. The 
cuspids, or eye teeth. in. The three molar 
teeth. A, shows the relation oi the i>erni;»- 
nent to the temporary te'>th. 

uul back, latorallv, and in conibina- 



253. A TooTii consists of an exposctl part, 



called 



the 



142 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

crown; a part concealed in the gum and jaw, called the 
root or fang, and at the junction of the fang and crown a 
constricted portion, called the neck The teeth differ in 
size, in form of crown, and in number of fangs. They 
are, in the adult, thirty-two in number, and are divided 
into incisors, canines or cuspids, bicuspids, molars, and 
wisdom. 










- 




-.-'^ 


— — — 


\ I^H 


f 


IT |]B, 'nil 11 


711 ll 


l| 



Fig. 54. The Adult Tei;th.- 
4, 5, Small grinders (bicuspids). 



-1,2, The cutting teeth (incisors). 3, Canine (cuspid). 
6, 7, 8, Grinders (molars). 9, 9, Neck of the tooth. 



254. The incisors have one fang and a wide, thin, chisel-shaped 
crown, and are well adapted for cutting purposes. The canines have 
a sharp-pointed crown and one long, single fang. The bicuspids, or 
pr€-77iolars, have two pointed cusps on the crowns. The single fang 
in the lower jaw is deeply grooved, but in the upper is partly cleft. 
The 7nolars, or grinders, have large, cuboidal crowns, with four or 
five cusps. The two front molars of each side in the lower jaw 
have two fangs ; in the upper, three ; while in the wisdom tooth 
they are usually united in a mass. The teeth are firmly secured in 
the socket by the firm, fibrous^ pinkish structure called the gum. 



253. Parts of a tooth ? Differences ? Number ? Kinds ? 



THE DIGESTIVE ORGANS AND DIGESTION. 



143 



Fig. 64a. 



255. The milk teeth are twenty in number, ten in each jaw: 
m.2 c.l i.4: c.l m.2 ^ ^^^ rj.^^^ ^^^^^^ ^^ ^pp^^^ ^^^^^^ 
m. 2 c. 1 i 4 c. 1 m. 2 

the seventh month, and are completed about the twenty-fourth 

month. These teeth are shed, and are succeeded at intervals by 

the permanent teeth, thirty-two in number, sixteen in each jaw : 

w. 3 b.2 c.l i. 4 c.l b. 2 m. 3 on t't, +4- +u 

— - — — ^-- — -— = 32. The permanent teeth 

m. 3 6. 2 c.l z. 4 c. 1 6. 2 m. 3 ^ 

appear earlier in the lower than in the upper jaw. The incisors, 

the earliest, appear between the fifth and 

seventh years, the wisdom teeth between 

the seventeenth and twenty-fifth years, and 

the others at variable dates between these 

limits. 

256. The hard portion of the tooth is com- 
posed of dentine, cement, and enamel. The 
dentine forms the greater part of the tooth. 
It contains more mineral matter and is 
harder than bone. It consists of microscopic 
tubes, called dental tubuli, which have hard 
walls and are bound together by a hard in- 
termediate substance. The cement is a layer 
of true bone (505), which covers the fang. 
Its outer surface is attached to a fibrous, 
sensitive membrane analogous to the peri- 
osteum (16), which serves to fasten the tooth 
in the socket. The enamel, the hardest of 
all animal textures, is the white substance 
which protects the crowns of the teeth. It 
contains 96.5 per cent, of mineral matter. 
It is made up of minute, hexagonal, pris- 
matic rods, arranged closely together on the 
dentine. On the crown the enamel rods 
are vertical, but on the sides they are at 
first oblique and then horizontal. Near 
the dentinal surfaces are minute interstices, which are su{)posed to 
be for nutritive permeation. In the interior of the tooth is a cavity, 
which contains a soft substance called the pulp. The pulp consists 
of areolar tissue, supplied with vessels and nerves entering through 




¥iG. 5^(1 (Leidii). Vertical 
Section of a Molar Tooth, 
moderately magnified. 1, 
Enamel, the lines of which 
indicate the ananiiement 
of its columns. 2, Dentine, 
the lines indicating the 
course of its tubules. 3, 
Thin lamina of tlie dentine 
forming the wall of the 
pulp-cavity, the dof.s indi- 
cating the orifices of the 
dental tubuli. 4, Cement. 



144 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



the fang, and is the remains of the papillae on which the tooth was 
originally formed. 

257. The Salivary Glands embrace three pairs, — the 
parotide seated on the sides of the face, between the ear and 
the lower jaw; the submaxillary, beneath the horizontal 
part of the lower jaw; and the sublingual^ beneath the 
tongue. The glands consist of numerous lobes and lobules. 
The product of its secreting tissues, the saliva, is conducted 



Fig. 55. 



Fig. 56. 




Fig. 55. The Mouth and Neck laid open.— 1, The teeth. 3, 4, Upper and lower jaws. 
5, Tlie tongue. 7, Parotid gland. 8, Sublingual gland. 9, Trachea (windpipe). 10, 11, 
CEsophagus (gullet). 12, Spinal column. 13, Spinal cord. 

Fig. 56. A Side-View of the Face.— 1, 2, Trachea. 3, CEsophagus. 7, Submaxillary. 
8, Parotid gland. 9, Duct from the parotid gland. 4, 4, 4, 5, 0, Muscles. 

to the mouth by ducts. In the mouth, the saliva is a 
glairy, frothy, limpid fluid. It contains but a small amount 
of solids. It serves to moisten the food, to assist in masti- 
cation and swallowing, and to commence the change of the 
starch into grape-sugar. 

[Experiment. — Place a bit of dry bread in the mouth, hold it there a few minutes ; then 
notice the change produced.] 



257. Of the salivary glands? Number? Position? Composition? 
Secretion ? Appearances of saliva ? Uses ? 



THE DIGESTIVE ORGANS AND DIGESTION. 145 

258. Mastication and Insalivation. — This process 
is performed by parts of the mouth, consisting of the teeth, 
the jaws, the muscles which move the lower jaw on the 
upper and those which act on the cheeks, lips, tongue, and 
pharynx, and the glands. It consists in the cutting, crush- 
ing, and grinding of the food-substances, the mixing of the 
same with air, saliva, and mucus of the mouth, and the 
forming of the materials into a soft, pulpy mass. The 
action is quite complicated, but each part, muscle, and 
secreting tissue is so arranged as to perform its proper 
action at the correct moment, the muscles moving the jaws, 
the tongue, lips, and cheek keeping the mass between the 
proper teeth, the glands, under the stimulation of the 
motions, giving forth abundant fluid, and the soft palate 
keeping the entrance to the throat closed, so that breathing 
through the nostrils may not be impeded during the process. 

259. The Pharynx (158) is the musculo-membranous 
canal into which the mouth opens behind. It is provided 
with three pairs of constrictor muscles (Fig. 56, 4, 4, 4). 
It opens below into the oesophagus and larynx, and is 
common to both food and air in its middle portion. 

260. The QiIsopitagus, or gullet, is a musculo-mem- 
branous tube leading from the pliarynx to the stomach. 
It is the narrowest portion of the alimentary canal. 

261. Swallowing, or Deglutition, is divided into 
three stages. (1.) The mass of food is forced by the tongue 
through the fauces into the pharynx. This is under the 



258. What parts are engacjed in mastioatini;- food? Tlio action? 
Duties of each part? Breathinti;? 

259. Describe the pharynx. The muscles. The opcning-s. 

260. What of the ffisopha.«>-us ? 

261. Swallowing: first stage? second? third? AVhon docs the 
will act? 

G j -13 



146 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



Fig. 57. 



control of the will. (2.) In this stage the bolus must pass 
through the portion of the pharynx common to food and air, 

and hence it must be quickly 
performed. It is done by 
a series of contractions con- 
trolled by the reflex centres, 
not by the will. (3.) The 
passage through the gullet is 
done by progressive muscular 
contractions, peristaltic, from 
above downward, and is in- 
dependent of the will. 

262. The Stomach, the di- 
lated part of the alimentary 
canal into which the oesopha- 
gus opens above, is a somewhat 
pear-shaped sac. It is placed 
on the leftside of the abdomen, 
and under the diaphragm. The 
larger end is towards the left 
side, while the smaller or jpy- 
loric part, which ends in the 
small intestine, points to the 
under side of the liver. Its 
capacity is variable, ranging 
from a teaspoonful up to about 
three pints. Its walls are 
composed of four layers. The 
outer or serous layer — thin, transparent, and smooth — is a 
part of the peritoneal lining of the abdomen. The fibres 
of the muscular layer are arranged lengthwise, circularly, 

262. The stomach : shape ? Position ? Capacity ? Layers or coats ? 
Glands? Secretion? Characters of the juice? 




fiG. 57 (Leidy). The Stomach and In- 
testines. — 1, Stomach. 2, Duodenum. 
3, Small intestine. 4, Termination of the 
iletim. 5, Csecum. 6, Vermiform appen- 
dix. 7, Ascending colon. 8, Transverse 
colon. 9, Descending colon. 10, Sigmoid 
flexure of the colon. 11, "Rectum. 12, 
Spleen. 



THE DIGESTIVE OEGANS AND DIGESTION. 



147 



and obliquely. The areolar layer contains blood-vessels and 
lymphatics. The mucous or inner layer is provided with 
multitudes of glands, which secrete the Gastric Juice. 
This fluid is colorless and watery, and has a sour taste and 
odor. It contains free hydrochloric acid, and a ferment- 
body called pepsin. 

263. Function of the Stomach. — Its secretion, gas- 
tric juice, has the power of changing the msoXwhlQ proteids 
(beef, eggs, legumin) into soluble and diiFusible substances, 

Fig. 58. Fig. 59. 





Fig. 58 {Leidy). Small Portion of the Mucous Membrane of the Stomach, with 
THE Embedded Gastric Glands.— 1, The glands. 2, Orifices of the glands. 3, Epithelium 
of the mucous membrane. Moderately magnified. 

Fig. ,59 {Leidy). Mammillae of the Mucous Membrane of the Stomach, moderately 
magnified, exhibiting the orifices of the gastric glands. 

called peptoues (274). The muscular contractions churn the 
contents of the stomach and thoroughly mix i\\Q food with 
mucus and juice. These motions are independent of the 
will. When a portion of the food is reduced to a soft 
pulp, it is forced into the intestine. 



263. Action of gastric juice ? Of the muscles ? Further action of 
the foods ? 



148 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



264. The Small Intestine extends from the pylorus 
of the stomach to a valve-like opening at the entrance of 
the large intestine, near the right groin. It is about twenty 
feet longj and lies in coils in the middle and lower part of 



Fig. 60. 



Fig. 61. 




Fig. 60 (Leidy). Diagram of a Vertical Section of the Mucous Membraxe of the 
Small Intestine, highly magnified. — 1, Fibrous layer, in which the blood-vessels are 
distributed. 2, Basement membrane. 3, Young nucleated cells. 4, Layer of columnar 
cells. 5, 6, Cells in the act of being shed or thrown off. 7, Free ends of the columnar 
cells, exhibiting their six-sided foim. 8, A single columnar cell, exhibiting its form at 
all parts. 

Fig. 61 {Leidij). Mucous Membrane from the Jejunum. — 1, Villi resembling val- 
vulae conniventes in miniature. 2, Tubular glands : their orifices, 3, opening on the 
free surface of the mucous membrane. 4, Fibrous tissue. Magnified. 



the abdomen. It is from one to one and three-fourths of 
an inch in diameter. It is supported and held in place by 
a broad double fold of the peritoneum (246), enclosing 
blood-vessels and nerves, called the mesentery. The first 
ten inches of this intestine is known as the duodenum, 
into which the ducts from the pancreas and liver empty. 
The jejunum includes the upper two-fifths of the remainder, 
and the ileum the lower three-fifths. The interior of the 
tube shows many transverse projections, extending half 
or two-thirds around the tube, the vahulse conniventes, and 

264. Small intestine : extent? Length? Position? Size? Mode of 
suspension? Diyisions ? Yalvulae conniventes? Yilli? Glands? 



THE DIGESTIVE ORGANS AND DIGESTION. 149 

an immense number of minute thread-like processes, the 
villi (see Fig. 63). When immersed in water, these villi 
stand up, and thus resemble the pile of velvet. There are 
many glands in the mucous membrane layer. 

265. The movement forward of the contents of the intestine 
depends upon the longitudinal and circular muscular fibres of the 
tube. This peristaltic (84) action consists of slow, successive, wave- 
like contractions, chiefly of the circular fibres, extending from the 
upper part gradually to the lower part of the canal. The series of 
contractions force the intestinal contents along. These contractions 
may occur, as in a portion cut out of the body, independently of 
the central nervous system. Their essential stimuli arise in the 
nerve-ganglia seated in the intestinal walls, but the movements are 
modified by influences passing over the vagi (383) and sympathetic 
nerves (386). 

266. In vomiting, the oesophageal opening of the stomach is 
dilated, and the increased pressure of the abdominal walls, together 
with holding back the breath, forces the contents of the stomach 
out. The pylorus is usually closed. When the gall-bladder is full, 
a large flow of bile takes place into the duodenum, especially during 
vomiting, and this gall may find its way to the stomach and be sub- 
sequently ejected. The nervous mechanism of vomiting is com- 
plicated, and as yet but little understood. There appears to be a 
vomiting reflex centre in the medulla, near the respiratory centre 
(185). This centre maybe excited by thoughts, odors, brain-disease, 
tickling of the fauces, irritation of the stomach (mustard-water), 
drugs, irritation of the intestine (hernia), or renal or bile stones. 

267. The Large Intestine is from five to six feet 
long, from one and a half to two and a half inches wide, 
and has a wrinkled and sacculated appearance. Its nnicous 
membrane is smooth, and has, in depressions, a few glands. 
There are no villi. 

268. Commencing near the right groin, it ascends on the right 



267. Large intestine : length? Size? Appearance? Lining? 

268. Course? Divisions? Valiio? Yormit'onn appendix ? Func- 
tion of the latter? 

13* 



150 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



side to the liver, passes across behind the umbilicus to the left side, 
descends to the iliac hollow of the left innominata, makes a double 
curve, enters the pelvis, and passes down, resting on the sacrum and 
coccyx. The portion in the pelvis is known as the rectum, and the 
other portion as the colon. Between the small intestine and the colon 
is a valve of two segments, which prevents the contents of the colon 
from returning to the small intestine. Projecting from the lower end 
of the first part of the colon is a narrow, coiled, and tapering tube, 
called the vermiform appendix. In this cherry-stones and round 
objects sometimes stop, giving rise to pain and even inflammation. 
The appendix has no definite function in man. 

Fig. 62, 




Fig. 62 (Leirh/). Inferior Surface of the Liver. — 1, Right lobe. 2, Left lobe. 3, 
Posterior margin. 4, Anterior margin. 5, Quadrate lobe. 6, Caudate lobe. 7, Isthmus, 
or caudate process, connecting the latter with the right lobe. 8, 9, Longitudinal fissure. 
10, Transverse fissure. 11, Portal vein. 12, Hepatic artery. 13, Common biliary duct, 
formed by the union of the hepatic and cystic ducts. 14, Gall-bladder. 15, Inferior cava. 
IG, Hepatic veins. 17, Round ligament. 18, Anterior part of the suspensory ligaments. 

269. The Liver is a solid organ, of dark reddish-brown 
color. It weighs nearly four pounds, and contains in its 
tubes nearly one-fourth of the blood of the body. It is 
placed under the diaphragm, on the right side of the abdo- 



269. Liver: color? Weight? Contents? Position? Gall-bladder? 



THE DIGESTIVE ORGANS AND DIGESTION, 151 

men (Fig. 34). The Gall-Bladder is a pear-shaped 
sac, lodged in a groove on the lower side of the liver. It 
serves to hold bile until it is needed. 

270. Alcoholics, taken by the mouth, mostly enter the blood 
by the way of the gastric vessels (290), are at once moved on to 
the portal vein (103), and thus reach all parts of the liver. The 
regular use of undiluted alcoholics in excess (338a) induces abnor- 
mal growth of the areolar tissue of this large gland and an increased 
activity of the hepatic cells. When the acme of growth is reached, 
the new-growth areolar tissue contracts, and the liver becomes 
smaller than normal (243). The liver now fails to perform its 
normal functions. Alcoholic-hepatic disease intensifies the asso- 
ciated gastric, renal, and hgemic troubles (290, 305, 147a). 

271. Function of the Liver. — (1.) It forms glycogen 
(308) from the sugar and peptones of the portal blood, and 
stores it up in the liver. (2.) It gives out the glycogen, 
when it is wanted, in the form of sugar, which sugar is 
used in the nutrition of the body. (3.) It works over and 
changes the form and condition of the proteids of the 
blood. (4.) It forms from the blood the yellowish-green, 
viscid, bitter fluid, called bile, which aids in the absorption 
of fats (274). (5.) It forms urea (310) out of proteid com- 
pounds existing in the blood. 

272. The Pancreas is a long, narrow, pinkish gland. 
It is found behind the lower border of the stomach. In 
structure it resembles the salivary glands. Its duct dis- 
charges into the duodenum. 

Its secretion is viscid, colorless, odorless, and of an alka- 
line reaction. The pancreatic juice rapidly converts starch 
into grape-sugar, proteids into peptones (274), /afe into an 



271. Of glycogen ? Of its storage ? Of the proteids ? Of the bile ? 
Of urea? 

272. Pancreas: characters? Position? Resembhnice? Duct? Th'^ 
secretion? Its action on starch? On proteids? On fats? 



152 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

emulsion or a soap, and it is therefore remarkable for acting 
on all the principles of the food-stuffs (225). 

CHANGES EFFECTED IN THE FOOD-STUFFS IN THE ALI- 
MENTARY CANAL. 

273. The mixed food-stuffs, cooked or uncooked, in pass- 
ing along the alimentary canal, are subjected to the action 
of certain secretions, such as the salivary, gastric, and pan- 
creatic juices. Under the influence of warmth, moisture, and 
motion, these secretions produce such changes in the ordi^ 
nary foods that, from being largely insoluble, they become 
largely soluble, — the starches being converted into sugars ; 
the proteids, into peptones ; and the fats, into emulsions, or 
soaps, — and the major part directly or indirectly enters the 
blood-current, and the lesser part is discharged as excrement, 

274. Changes. — In the mouth, tlie mixed food, as flesh, 
bread, vegetables, etc., is broken into small pieces, is moist- 
ened with saliva, mixed with air and saliva, and formed 
into a bolus for swallowing (258). Some of the starch is at 
once converted into soluble grape-sugar. In the stomach, 
the presence of the food, made more or less alkaline by the 
saliva and mucus, excites the glands of the stomach to 
great activity. The contents of the stomach become more 
and more acid ; the change of starch into sugar is lessened 
or arrested; the fats remain unchanged; the proteid en- 
velopes of starches and fats are loosened ; the natural 
bundles of flesh and vegetables fall asunder, and the fats, 
starches, oils, and protoplasm become more exposed ; the 

273. What juices act on tbe food- stuffs? What changes are in- 
duced? What results? 

274. Changes in the mouth? In the stomach? What is a pep- 
tone? Appearance of chyme ? Changes in the small intestine ? In 
the laro-e intestine? 



THE DIGESTIVE ORGANS AND DIGESTION. 153 

protoplasm is dissolved, and the proteids (215) are con- 
verted into peptones. A Peptone is a proteid. It is 
soluble in water, is highly diffusible, — i.e., it passes through 
moist animal membranes with ease, — and is not coagulated 
by heat. The food is now imperfectly dissolved, and 
forms a turbid, grayish liquid, called chyme. This latter, 
together with large lumps, is from time to time ejected 
through the pylorus into the duodenum. In the small 
intestine, by the action of the bile (271), the pancreatic 
juice (272), and the intestinal secretions, together, the re- 
maining proteids are converted into peptones, the starches 
into sugar, and perhaps into lactic acid, and the fats are 
made into an emulsion, or into a soap, and. are thus in a 
state which enables them to be taken into the portal blood- 
vessels (103) or into the lacteals (277). In the large intestine, 
the contents again become acid, owing to fermentation. A 
certain amount of cellulose (221) may be here digested. 
The great work, however, is absorption of the liquids con- 
tained in the fluid mass passed through the ileo-ccecal valve, 
so that when the mass reaches the rectum it has become 
firm, closely packed, and somewhat dry. 

275. Osmosis. — When two different liquids, as blood 
and chyme, are separated by thin membrane, as the mucous 
membrane and the thin capillary walls, it is noticed (1) 
that the liquids mix through such membranes, and (2) that 
the quantities passing in opposite directions are unequal. 
The mixing of the fluids through membrane is called os- 
mosis. In the case of blood and chyme, the greater current 
is towards the blood, owing to the relative physical and 
chemical conditions of the fluids. AYatery solutions usu- 



275. What occurs throug-h meinbrano.<? What is osmosis? Diroc- 
tion of the currents? What osmose easily ? 



154 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



ally osmose readily. Colloids, like gelatin, other proteids, 
starches, and fats, osmose slowly, or not at all. 

276. Absorption. — The water, the soluble salines, and 
crystaUine organic compounds may be absorbed from any 
part of the canal througli osmosis of the veins and capil- 
laries. By the help of the circulation, an almost unlimited 
quantity of fluid may be absorbed. The sugars and pep- 
tones, in part, are taken into the blood-current through the 
vessels in the walls of the stomach. The largest and most 

P'iG. 63. 






'^ ' " f, 




Fig. 63 {Leubj) Portion of thf Mucot s Mfmbrane from the Ileum, moderately- 
magnified, exhibiting the villi on its free surface, and between them the orifices of the 
tubular glands. — 1, Portion of an agminated or clustered gland. 2, A solitary gland. 
3, Areolar tissue. 

important part of the digested material leaves the canal 
during its passage along the small intestine, partly into the 
portal vessels (103) and partly into the lacteals. A con- 
siderable quantity of peptones and sugars passes into the 
portal vessels. The great mass of the fats which enter the 
system from the intestines passes through the lacteals. 

277. The Lacteals commence within the villi of the 
small intestuie (264) by closed extremities. They consist 

276. Place of absorption of watery" solutions? Of sugars? Of pep- 
tones ? Of the fats ? Where is absorption most active ? What two 
chief channels ? 

277. Commencement of the lacteals? Their structure? Nature 
of villi ? Appearance of chyle ? Ending of lacteals ? Describe the 
thoracic duct. 



THE DIGESTIVE ORGANS AND DIGESTION. 



155 



either of a net- work of tubes, 
which, at the base of the viHi, 
pass into larger tubes, or 
of a single, closed, dilated, 
minute tube, ending in a net- 
work of tubes. The villi con- 
tain some muscular fibres and 
an arterial and venous twig, 
which form a net-work out- 
side the lacteal. During 
intestinal absorption, these 
lacteals are seen to be dis- 
tended with a whitish or 
bluish fluid, called chyle. 
Leading from each villus are 
tubes, which run into larger 
tubes lying in the mesentery 
(264). These tubes termi- 
nate in firm, ovoid or round- 
ish bodies, called mesenteric 
glands. From these glands 
thread-like tubes lead to a 
larger tube, the thoracic duct, 
lying in front of the verte- 
bral column. This duct is 
from eighteen to twenty 
inches long, has numerous 
valves opening towards the 
neck, and empties into the left 
subclavian vein (Fig. 64, 3). 
278. Chyle.— Tn a fast- 

Fio. 04 {Leidii). View of the Ctreat Lvmpiiatio Trvn-ks.— 1. '_\ Tlioia.- 
right lyiupluUic duct, fi, Ti.vinphatics of (lu- thv-h. (\ Tliao lyinphati^-s, ' 
phatics. 8, Intei-costal l.vmi.hatics. „. Siiiu-rior cava. /.. I.oft inuomiiiato 
inuonihiato vein. <?, Aorta, c, InlViiMi- cava. H. I.oft subclavian vein. 




c .hu t. 
. l.umb 
voin. , 



I. Tl.o 
vr \\n\- 
, Uis;ht 



156 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



ing animal, the contents of the thoracic duct are clear and 
transparent. Shortly after a meal they appear milky and 
opaque. Chyle is a mixture of the lymph (295) coming 
from the rest of the body and of the white fluid seen in 
the lacteals. Chyle readily coagulates, like blood (120), 
_ but the clot is not firm. It 

assumes a pinkish color on 
standino;. It consists of 
fibrin, of a large number of 
white corpuscles, of a small 
number of red corpuscles, 
and of many oil globules. 
It mixes with the blood in 
the left subclavian vein. 



279. Movements of Chyle. 
— Though the villi may act as a 
kind of muscular suction-pump, 
yet the exact method of the tran- 
sit of the fat from the intestines, 
through the walls of the villi 
and of the intervening tissues, to 
the lacteals, is not known. Hav- 
ing reached the interior of the 
mesenteric tubes, the liquid con- 
tents are directed by the numer- 
ous valves, and their flow is aided 
by the general muscular move- 
ments, the suction of the subcla- 
vian vein (owing to the lessened 
blood-pressure ruling therein), by 
the influence of the inspiratory 
movement, and by the continual 
pressure of the intestinal contents. All these forces working to- 




FiG. Gj.— 1, 1, A ertebial column. 2, 2, 2, 
Lacteals. 3, 3, 3, Thoracic duct. 4, Stomach. 
5, Colon. 7, Liver.- 8, 8, Diaphragm. 9, 
Heart. 10, 10, Lungs. 11, Large vein 
into which the thoracic duct opens. 



278. Appearance of chyle ? Composition ? 
does it mingle with the blood ? 



Characters ? Where 



THE DIGESTIVE ORGANS AND DIGESTION. 157 

gether cause the contents of the lacteals and of the lymph-ducts 
(295) to be discharged into the general blood-current. 

280. Summary of Digestion. 

In the mouth : 

Mastication and insalivation. 

Starches partly changed to sugar. 
In the stomach : 

Thorough mixing of ingredients. 

Breaking up of the proteid envelopes. 

Setting free of starch, fats, and protoplasm. 

Proteids changed to peptones. 
In the small intestine : 

Starches changed to sugars. 

Proteids changed to peptones. 

Oils emulsified or saponified. 

Summary of Absorption. 
From the mouth : 

Water, salts, sugar. 
From the stomach : 

Water, salts, peptones. 
F^'om the small intestine : 

(a) Portal veins, — water, sugar, peptones. 

ib) Lacteals, — emulsions, soaps. 
From the large intestine : 

Water, salts, sugar (?), peptones (?). 

Hygiene. 

281. Indigestion, or Dyspepsia. — Difficulty and im- 
perfection in the digestive process arise under a variety of 



280. Suininary of dii^-ostion? Of absori^tion? 

281. What is dysjiopsiH? Causes of iiuliij;ostion ? 

14 



158 ANATOMY^ PHYSIOLOGY, AKD HYGIENE. 

circumstances. Indigestion may occur with certain articles 
of diet (cheese, oysters, strawberries, etc.), or with disturb- 
ances located in the stomach or intestines, or in both. 
Among the common causes of indigestion are excessive 
eating (334), too rapid eating, insufficient mastication or 
insalivation, irregularity of meals, too frequent occurrence 
of meals, or the reverse, improper quality of the food, the 
drinking of too much cold water during or immediately 
after taking food, the excessive use of tea (238), the abuse 
of alcohol (245), and the injudicious use of condiments. 

282. The Quantity of Food necessary to the system 
varies, being affected by age, occupation, temperament, 
habits, temperature, amount of clothing, health, and mental 
state. The supply must equal the waste of the system 
(338), and, in children, the demands for growth (337). 
The supply should be in the form of plain food, plainly 
served, and eaten in moderation. The quantity should be 
kept well within the digestive capacity of the individual. 
The object to be kept in view in the use of food is not the 
development and maintenance of a fat, plump body, but 
of a sound body. On the diminution or cessation of active 
employment, especially physical, practise self-denial, as re- 
gards the amount of food, until the system has become 
accustomed to the new conditions. On the advent of warm 
weather reduce the amounts of fat and proteids in the diet, 
and by so doing indigestion and " biliousness" may be pre- 
vented. 

283. Physical State of the Food. — The more finely 

282. The amount of food, how affected? The supply? In what 
form ? Object in feeding? Management under less bodih' work ? In 
the spring ? 

283. The conditions for easy digestion ? About eggs ? Advantages 
of flesh ? Spallanzani's experiments? What suggestion? 



THE DIGESTIVE OEGANS AND DIGESTION. 159 

divided tiie food, the less the proteid portions are sheltered 
by insoluble envelopes, like the cellulose of vegetables and 
grains, and the more thoroughly it is mixed with air and 
the saliva, the more rapid and easy is the gastric digestion. 
Well-beaten white of eggs is more easily digested than 
boiled white, hard-boiled yelk than boiled white, and hard 
boiled white than fried white (231). Hard-boiled eggs are 
more difficult of digestion than roasted or boiled flesh, 
because the gastric juice can only attack the former on its 
outer, impervious surfaces ; but the flesh, under the action 
of warmth, moisture, and motion, breaks up into its fibres 
and muscular disks (71), and thus more surface is exposed 
to the action of the juice. Spallanzani's experiments with 
perforated tubes containing food, placed in the stomach of 
animals, gave the following results : food moistened with 
saliva was most quickly digested ; then food moistened with 
water ; and, lastly, food not moistened at all. Hence the 
importance of careful, wise cooking, of fine division, and 
of complete insalivation of all kinds of food. 

284. Bad Teeth are a fertile source of dyspepsia. A 
person having very irregular, decayed, or defective teeth is 
unable to divide his food thoroughly or to incorporate the 
same well with saliva, and, as a result, extra digestive labor 
is thrown upon the stomach and pancreas. 

285. The dentist and cook may be of much service to 
the person having defective teeth. Teeth having cavities 
ought to be cleaned and plugged. The best filling is gold 
foil. Badly-decayed teeth should be removed, as their 
presence is hurtful to the adjacent teeth, taints the breath, 



284. Influence of bad teeth ? 

285. What can the dentist do ? Of Mrtilu-inl tooth '? AVhat can the 
cook do? or manasi-oniont of food in the tnoutli? 



160 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

and acts injuriously on the food passing over them. It is 
better for the health, in the absence of natural teeth, to use 
artificial ones than to struggle along without them. A good 
cook, by the judicious selection and careful preparation of 
the food, can be of much assistance to persons having de- 
fective teeth. Light puddings, soups, minced meats, eggs, 
milk, etc., require little mastication. They should not, 
however, be ^' bolted," but ought to be well rolled about 
in the mouth, in order to mix considerable quantities of 
mucus and saliva with them before swallowing. 

286. Care of the Teeth. — The teeth should be kept 
clean by cleansing them with tepid water after each meal. 
Quill, wood, or ivory picks are preferable to those of metal. 
The teeth should be carefully brushed, outside and inside, 
morning and evening. The occasional use of a fine soap, 
followed by careful rinsing, is advisable. No coarse or 
acidulated tooth-powders should be employed. Avoid 
sudden extremes in temperatures of food and drink. The 
cracking of hard objects with the teeth is not judicious. 
Tobacco injures the enamel, discolors the teeth, debilitates 
the gums, and taints the breath, while it offers no compen- 
sating advantage to the digestive functions (412). 

287. Frequency of Eating. — Man in a savage state 
feeds with great irregularity. When the food is abundant, 
he devotes himself to eating, drinking, and sleeping; but 
when it is scarce, he contents himself with one meal a day. 
In either case the quantity taken is enormous. A good 
calf, weighing two hundred pounds, makes only one meal 
for four or five Yakuti ; a reindeer, a meal for three only 



286. Teeth-cleansins: ? Toothpicks? Soap? Powders? Tempera- 
ture ? Hard substances ? Tobacco ? 

287. Frequency of eating in the savage state? In Japan? In 
Rome? In Europe? Distribution of food? 



THE DIGESTIVE ORGANS AND DIGESTION 161 

(Cochrane). The Japanese "jinriki," confined to a diet 
of beans, millet, rice, and dried fish, eats five or six times 
daily ; the boatmen, four to six ; the field-laborers, three 
to five ; and the official class, two to four. The Romans 
had two meals a day, — the dinner at 9 am. and the cere- 
monious supper at 4 p.m. Until recent times there were 
but two meals a day in civilized Europe. Experience 
shows that in America three meals, each meal being of 
simple quality, is the best division for efficient activity. 
The distribution of the day's food, according to Dr. E. 
Smith, should be about one part for the evening meal, one 
and one- half parts for breakfast, and two parts for dinner. 

288. Under ordinary circumstances, it is best for healthy 
persons to take no food between meals. Children should have 
their food oftener than three times in the twenty-four hours. 
Invalids ought strictly to follow the diet-directions of their 
medical adviser. Light conversation, enlivening wit, and 
genial humor promote digestion. Unpleasant topics, la- 
bored discussions, business affairs, etc., should be banished 
from table-conversation. 

289. Improper Eood. — To a certain person, the im- 
proper quality of a food may depend upon the nature of 
the food itself, upon the manner in which it has been pre- 
pared, or upon its having undergone changes, like decom- 
position or fermentation. 

The food which is suitable for the soldier, sailor, or 
laborer may be, and is often, very unsuitable for the student 
or the professional man or Avoman. Articles which the 

288. Of oatinc; between meuls ? Intervals for oliildron ? For in- 
valids? Influence of conversation? 

289. Causes of improper quality of food? Of diftoronces in indi- 
viduals? Of a diet for students? Prevention of dyspepsia? Suitable 
foods ? 

I 14* 



162 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

former class can take with impunity, digest with ease, and 
derive energy from, would cause pain, loathing, and digestive 
troubles and be of no advantage to the latter. Other things 
remaining the same, the student, the professional man, the 
seamstress, and others engaged in sedentary pursuits need 
a higher grade and more readily assimilable kinds of food 
than do the classes engaged in active, out-of-door pursuits. 

The cooking of the food for the sedentary classes demands 
more care, wisdom, and skill than are commonly given to it. 
To prevent dyspepsia, or to remedy dyspeptic conditions, 
the regulation of the diet-list is the chief thing demanding 
attention. In all cases of early indigestion, articles known 
to be difficult of digestion — pastry, cheese, certain fruits 
and vegetables, fresh white bread, and most fancy dishes — 
must be avoided. Pork, veal, and salted meats are to be 
used with caution. Fresh beef and mutton, not too fat, 
and carefully baked or boiled, are most suitable meats. 
Light soups, chicken, game, white fish, yelk of eggs, milk, 
rice, barley, and oat-meal are to be commended. 

290. Alcoholics (242), for the most part, rapidly enter the 
blood by the way of the gastric capillaries, very little reaching 
the intestinal surfaces. Hence the stomach and the liver (270) 
bear the brunt of their early actions. Taken habitually in large 
quantities, they lessen the appetite. In the temperate, small doses 
excite increased secretion ; moderate doses excite the secretion, 
but its alcohol precipitates the pepsin, and thus hinders or stops 
gastric digestion. The habitual use of undiluted alcoholics, after 
a time, induces changes in the walls of a hardening, thickening, 
and puckering nature (243), and cause excess of formative action 
in the gland tissue and the interglandular areolar tissue (250). 
At first the gastric juice is augmented, though of inferior quality ; 
later, owing to pressure, the secretion is lessened. After a time the 
areolar-tissue increase reaches its acme, and contraction of that 
tissue occurs. Now the secreting cells, under increasing pressure, 
waste or change to fat, and gastric secretion wanes. Chronic indi- 
gestion is established. Starches and sugars introduced into such 



THE DIGESTIVE OKGANS AND DIGESTION. 163 

a stomach rapidly undergo acid fermentation. Proteids are not 
digested. Proteids and fats are so altered that intestinal digestion 
is hindered or stopped (274). Hence the blood is unable to receive 
normal new supplies (276). 

291. Pkevention of Dyspepsia. — To counteract the 
tendency to dyspepsia, interesting physical exercise (riding, 
rowing, lawn-tennis, etc.) should be taken daily, and at 
regular hours, though not immediately before or after a 
meal. The ventilation of the working- and sleeping-rooms 
needs constant attention (204). Abstinence from injurious 
habits, such as excessive smoking of tobacco and intemper- 
ance in the drinking of tea (238) and alcoholics, must be 
observed. The action of the skin is to be encouraged by 
cool baths, the skiu quickly dried, and by douche-bathing, 
with occasional warm or Turkish baths. The wearing of 
flannel next to the skin must not be neglected, as it not 
only prevents the chilling of the abdomen, but tends to 
relieve constipation. 

The functional exercise of any organ abstracts fluids, sanguineous 
and nervous, from other parts of the body, thus weakening those 
parts for the time. Severe exercise of muscle concentrates the 
forces in the muscle ; severe exercise of the brain concentrates the 
forces in the brain ; and so with the vocal and other organs. After 
sev'ere exercise, from thirty to forty minutes should be allowed 
before eating, for restoring equilibrium to the system. The student, 
farmer, or mechanic who hurries from his toil to his dinner to " save 
time" will, in the end, lose more time than he saves. After eating, 
the digestive organs need, for a time, the chief use of the vital 
forces, and if these arc habitually expended elsewhere, as in study 
or labor, digestion will be arrested, the chyle cheated of its proper 
elements, and headache, dulness, and general derangement will 
follow. Moderate exercise of the muscles, a social chat and a hearty 
laugh, aid digestion, and tend "to shake the cobwebs from the 
brain." These directions are particularly applicable to the am- 

291. Influence of exercise in dyspepsia? Of ventilation? Of 
abstinence? Ofbatliino-? Of dothinir? 



164 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

bitioiis student who feels that he must " save time" and " must have 
the lesson." Let him try the experiment, and he will soon find that 
in the after-dinner hour his lesson is better learned when he spends 
half the hour in recreation and the other half in close application. 
Many students are obliged to give up their course of study, from 
simple neglect of these rules. 

292. Constipation is very prevalent among sedentary 
persons, as students, writers, females, clerks, and operatives 
in factories. The main causes are want of daily, active 
exercise, inattention to a proper diet, and neglect of 
nature's needs. In a majority of cases, constipation can 
be remedied by eating well-cooked white flour compounds, 
cracked wheat, oat-meal, hominy, etc., sub-acid fruits, and 
a moderate amount of boiled or roasted lean meats. The 
habit of going to the stool daily at the same hour, even 
though at first there is no response to the eflPort, should be 
persevered in. For children and the majority of per- 
sons, soon after breakfast is suggested ; for those suffering 
from evident rectal diseases, as tumors, piles, and fistulas, 
just before retiring. A recumbent position mitigates rectal 
pain. Active exercise, which calls all portions of the body 
into service, ought to be practised daily. As a remedial 
agent, body-flexion (533) should be practised at least three 
times daily. These movements accelerate the portal cir- 
culation (103), unload the congested, tense rectal veins, 
strengthen the muscular fibres of the rectum, and stimu- 
late the rectal glands. Daily evacuation of the intestines 
may be aided by friction over the abdomen, followed by 
faithfully kneading the abdominal walls, by a suppository 
of hard soap, or by an enema. The continued use of 
laxative and purgative drugs injures the system. 

292. Cultivation of habit in constipation? Change of diet? Ex- 
ternal agents ? Drugs ? 



CHAPTER IX. 



THE LYMPHATICS.— THE SPLEEN, THYMUS, ETC.— THE 
URINAKY SYSTEM. 



THE LYMPHATIC SYSTEM. 

293. This system includes the lymphatic vessels, the 
glands, and the lacteals (see 277). The lymphatic ves- 
sels consist of delicate tubes of nearly uniform size, pre- 
senting a knotted appearance because of the presence of 
valves. They are found in nearly every texture and organ 
of the body. The superficial set are placed just under the 
skin, and in the submucous tissues of the gastro-pul mo- 
nary and urinary tracts. The deep sets accompany the 
deep-lying blood-vessels. 

294. The Lymphatic Glands vary in size from a hemp- 
seed to an almond. They are round or oval in form, have 
a pinkish-gray color, and are made up of adenoid tissue. 
They are situated in the course of the lymphatic vessels and 
the lacteals. They may be easily found in the neck, in the 
armpit, in front of the elbow, in the groin, in the mesen- 
tery, and near the large blood-vessels. Occasionally, after 
an injury, bright-red streaks extend from the injured spot 
up the limb to certain small, firm, painful enlargements. 



293. What doos the lymphatic system include? Describe the ves- 
sels. Where located ? Of the two sets ? 

294. The glands: size? Shape? Locution? How recognized? Ap- 
pearance after injury ? 

1G5 



166 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Fig. 66. 




THE LYMPHATIC SYSTEM. 



167 



The red lines indicate the course of the superficial set of 
lymphatics of that part, and the enlargements the glands. 

295. The Lyjviph is a clear, colorless fluid found in this 
system of vessels. In general terms, it is blood without 
its corpuscles. This fluid passes from most tissues through 
the delicate walls of the tubes into the vessels, and is by 



Fig. 



Fig. 68. 



Fig. 69. 




Fia. 67. A Single Lymphatic Vessel, much magnified. 

Fig. 68. The Valves of a lymphatic trunk. 

Fig. 69. A Lymphatic Gland, with several vessels passing through it. 

them conducted to the general blood-current. Tlie lym- 
phatics of the right thorax, the right side of the head and 
neck, and the right arm, empty their contents into the right 

Fig. 66. A Representation of the Lymphatic Vessels and Glands.— 1, 2, 3, 4, 5, 6, 
The lymphatic vessels and glands of the lower limbs. 7, Lymphatic glands. S, The com- 
mencement of the thoracic duct. 9, The lymphatics of the kidney. 10, Of the stomach, 
n. Of the livei*. 12, 12, Of the lungs. 13, 14, 15, The lymphatics and glands of tho arm. 
16, 17, 18, Of the face and neck. 19, 20, Largo veins. 21, Tho thoracic duct. 



205. What is lymph ? Its movomouts ? AVhat sysloni of tub^ 



168 

lymphatic duct (Fig. 64, 4), and those of the rest of the 
body into the thoracic duct (277). 

296. Function. — The lymph continually passes into 
the blood-current a crowd of white bodies, which for the 
most part appear in the vessels after they have emerged 
from the glands. These adenoid glands may be one of the 
birthplaces of the v/hite corpuscles (119). The lymph also 
carries back to the blood materials present in the inter- 
stices of the tissues, \vhich may again be used in nutrition. 
Through slight abrasion of the skin or mucous surfaces, 
the virus of specific diseases (smallpox, vaccinia, farcy, and 
poison from a dead body) quickly enters the lymph-chan- 
nels, is conveyed to the blood, and, through the latter, in- 
fects the whole system. Hence the importance of using 
adhesive plaster to cover scratches or broken surfaces of 
the skin when handling dead bodies. 

297. The Spleen (Milt) (Figs. 57, 34) is a soft, 
dark-bluish body attached to the cardiac end of the stom- 
ach. Its size and weight vary more than those of any 
other solid organ of the body, owing to the variations in 
the quantity of blood which it contains. It has a strong, 
fibro-elastic coat, and is divided by numerous slender bands 
into spaces which contain a soft, bluish-red mass, called 
splenic pulp. The spleen has few lymphatics, and no duct. 

298. Function. — It has been removed from man without pro- 
ducing any marked permanent change in the economy. After a 
meal it increases in size, remains enlarged for some hours, and then 
returns to its normal size. This peculiar action may be connected 
with the manufacture of white corpuscles (119) and the destruction 
of the red. Evidently, active changes associated with digestion 

296. What appear beyond the glands? Speak of the birth of cor- 
puscles. What is also carried in the lymph ? 

297. What of the spleen ? Of its structure ? 



THE URINARY SYSTEM. 169 

take place in the spleen, but exact information as to their nature is 
wanting. 

299. Of the functions of the Suprarenal Bodies, found cap- 
ping the kidneys, nothing is definitely known. The same may be 
said of the Thyroid Body, seen on the front and sides of the tra- 
chea, below the larynx, and of the Thymus Gland, a temporary 
organ seated in the lower part of the neck of infants. This organ 
continues to grow until the second year, after which it gradually 
wastes away. 

THE URINARY SYSTEM. 

300. The Kidneys are two dense, dark-red, solid organs, 
situated in the back part of the abdomen, between the elev- 
enth rib and the innominate bone. Their shape is not very 
unlike that of the kidney-bean. They are placed back 
of the peritoneum, and are surrounded by areolar tissue 
liaving much fat, which serves to keep them of a uniform 
temperature. The artery [i^enal) leading to each kidney 
is short, but large, and is accompanied by a large vein. 
Leading from the cavity of the kidney is a musculo-mem- 
branous tube, the ureter, which terminates at the base of 
the bladder. This tul)e conveys the excretion called urine 
from the kidney. 

301. If a longitudinal section of the organ is made (Fig. 70), the 
solid substance is found to consist of an outer cortical portion 
and a deep-seated medullary portion. The conical masses of the 
medullary portion, from fifteen to twenty in number, form the 
pyramids. The apexes of the pyramids projecting into the renal 
pelvis (the funnel-shaped dilatation of the kidney) are called 
papilhe. The substance of the kidney is made up of minute, closely- 
packed tubes, the hdnili urini/eri, with blood-vessels, lymphatics, 
and nerves, held together by a soft material. It has been estimated 
that there are two million tubuli in each kidney. The tubuli arc 
lined with pavement or spheroidal epithelium (Fig. 42). 



300. Kidneys: Color? Shape? Position? Coverings? Vessels? 
Tubes? 

H 15 



170 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

302. Ueine.— Healthy urine is a clear, yellov/ish fluid, of a pecu- 
liar odor. *It has an acid reaction, and a specific gravity of 1.020. 
Fig. 70. Fig 71. 




Fig. 70 (Leidy). Longitudinal Section of a Kidney.— 1, Cortical substance. 2, 
Renal pyramid. 3, Renal papillae. 4, Pelvis. 5, Ureter. 6, Renal artery. 7, Renal 
vein. 8, Branches of the latter vessel in the sinus of the kidney. 

Fig. 71 {Leidy). Diagram of the Structure of the Kidneys.— 1, Two uriniferous 
tubules of the cortical substance lined with pavement epithelium. 2, Dilatation of a 
tubule at its extremity. 3, Branch of the renal artery ending in vessels which enter the 
dilatations as seen at 4, 5. 6, Knot of blood-vessels freed from its investment. 7, Veins 
emerging from the vascular knots. 8, Plexus formed by the latter veins among the 
uriniferous tubules, from which plexus originate the branches (rf the renal vein. 

303. Functions of the Kidneys. — The kidneys are 
excretive organs. Their function is to eliminate certain 



303. Describe the kidneys. Their function ? How affected? "What 
relation between the kidneys and the skin ? How is urea separated? 
What may also occur ? What of the urine ? 



THE URINARY SYSTEM. 171 

substances produced by the activity of other tissues. The 
waste inorganic and organic salts existing in the blood in 
solution are filtered, under varying blood-pressure (140), 
from the blood entering by the renal artery. There is an 
intimate correlation of the kidneys and the skin. When 
the blood flows freely in the skin, as in the summer, the 
perspiration is abundant, but the amount of urine voided 
in twenty-four hours is diminished ; in cold weather the 
converse is noticed. Urea (310) is always present in the 
blood. The protoplasm of the epithelial cells lining the 
tubuli withdraws the urea from the blood and discharges 
it into the tubuli. This does not appear to be filtration, 
but a true secretion process. The epithelium of the kidney 
may also change various nitrogenous matters existing in 
the renal blood into urea, and then remove it from the 
blood. The urine is continually produced, and finds its 
way, drop by drop, from the pelvis of the kidney, through 
the ureter, into the bladder. 

304. The Bladder is a muscular sac, lying, when empty, 
in the pelvis behind the pubic bones (Fig. 51). The medium 
capacity is two hundred and fifty cubic centimetres (about 
half a pint). It is lined Avith mucous membrane. The 
two ureters enter it at the base, and the Urethral Tube 
passes out through its neck. Its function is to hold the 
urine continually entering by the ureters, and to expel it 
at proper intervals. 

305. The retention in the blood of the nitrogenous prod- 
ucts of tissue-waste, owing to deficient or suppressed action 
of the kidneys, gives rise to headache, dizziness, nausea, con- 

304. Bladder: structure? Position? Cnpacity? Lining? Openings? 
Function ? 

305. Etfect of retention of nitrogen compounds in the blood ? Of 
urine in the bladder? 



172 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

fusion of ideas, and, if continued, a disease called urseraia. 
One of the most common factors in the production of disease 
of the kidneys is the steady use of alcoholics, especially dis- 
tilled liquors, — whiskey, rum, gin, etc. (243j. The forced 
retention of urine in the bladder leads to severe pain and 
over-distention. The latter may result in an inability to 
empty the bladder, in inflammation of the lining mem- 
brane, or in overflow. Hence the importance of obeying 
at once nature's pressing demands for the evacuation of 
this organ. 

805a. Alcohol used in large doses may induce an inflammatory 
renal condition due to its irritant action during elimination, for 
most poisons are excreted by the way of the kidneys. As in the liver 
(270), the continued action of alcoholics in excess (338a) in time 
produces " contracted kidneys." This condition is known by the 
diminution of the urine, the dry, harsh skin, the sallow, pinched 
face, the weakened system, and the general oedema and dropsy of 
advanced Bright's disease. 

Elimination. — There are no trustworthy series of experiments on 
record which prove that all the ethyl-alcohol administered in 
small doses to a healthy adult has been recovered in the excreta 
(306) as ethyl-alcohol. Binz (1870), in his series of careful ex- 
periments upon adults, administering daily in divided doses, in 
syrup, from one to one and a half ounces of absolute ethyl-alcohol, 
failed to detect alcohol in the lung exhalations. The largest 
amount he recovered in the urine in any case during twenty-four 
hours was less than six per cent, of the amount drank. In many 
of the trials he recovered none. Eeasoning from analogy, he in- 
ferred that none escaped by the skin. 

"At jDresent (1883) the weight of authority and the deductions 
of experiment are in favor of that view which maintains that, 
within certain limits (one ounce to one and a half ounces of abso- 
lute alcohol to a healthy man), alcohol is oxidized and destroyed 
in the organism, and yields up force which is applied as nervous, 
muscular, and gland force." — Bartholow, ''Mat. Med. and Therap." 
5th Editio7i. 



CHAPTER X. 

NUTRITION. 

306. The study of the preceding chapters has shown 
that certain materials known as foods (Chapter YII.) 
enter the blood, after undergoing more or less change, 
by venous absorption or lacteal absorption from the ali- 
mentary canal (280), by osmosis through the lung-tissues 
(177), and by absorption through the skin ; that the 
blood, in circulating through the organs of the system, 
especially the lungs and liver, is changed in its chemical 
and physiological characters ; that this blood in the capil- 
lary areas parts with certain portions and receives additions 
(143) ; that certain of these materials received in the capil- 
lary areas are of no further use to the system, and that 
these materials are excreted from the system by the way of 
the kidneys (303), the lungs (178), and the skin (48). 

307. Nutrition, or Assimilation, embraces the process 
or the change which the food-elements in the blood-current 
undergo for the production of energy and heat, and also for 
conveying from the system portions of waste matter. The 
forms in which the foods enter the system, and the condi- 
tions most favorable for their entrance, have been treated 
in Chapter VIII. The changes which they undergo in 



306. Wliat of the entrance of foods into the blood ? Of chanii-os in 
tlio blood? Of the gains and losses of the tissues? Of tbe modes of 
excretion ? 

307. What docs nutrition embrace? What is really known ? AVliat 
products have been partly studied ? 

15* 173 



174 AI^ ATOMY, PHYSIOLOGY, AND HYGIENE. 

the system, in the repair, building up, and reproduction of 
parts, and in the production of heat and other energy, are 
for the most part unknown (143). Glycogen, fat, urea, 
and uric acid have been only partly considered. 

308. Glycogen (271) is a sugar-producing substance, appearing 
in a pure state as a white, amorphous powder. It is found in the 
hepatic cells of a normal liver. It is elaborated from the portal 
blood, containing proteid foods or starch foods, but not from fat 
foods. It is stored up during active digestion, and thus acts as a 
reserve store of carbo-hydrates. According to the demands of the 
system, the insoluble glycogen is changed in the liver into the 
soluble sugar which appears later in the hepatic veins. The part 
which this sugar, gradually set free by the liver, plays in energy- 
and heat-production has not been elucidated. A certain amount 
of sugar is normal to the blood. An excess appears to be injurious. 
This excess is removed in two ways: (1) by the kidneys, giving rise 
to diabetes, or sugar in the urine; (2) by the liver-cells, changing 
the excess in the portal blood into insoluble glycogen. Experi- 
ments indicate that the glycogenic function of the liver is subject 
to the central influence of a nerve-centre located in the medulla, 
near the vaso-motor centre. 

309. Fat. — Of all the tissues of the body, the fat fluctuates most 
(21). It is formed the most quickly, and the most quickly removed. 
Experiments and observation show that it is formed by the active 
agency of the protoplasm of the fat-cell, and that it is stored up as 
fat granules or drops. Under suitable conditions, the fat of the 
food may be stored up in the body as fat. In most cases it is 
formed in the system out of something which is not fat, as shown 
in the milk- and fat-production of cows. The carbon elements of 
the fat may be derived from proteids, from carbo-hydrates (starches 
and sugar), from fats, or from a mixture of the same. Experience 
shows that carbo-hydrates are most efficacious in producing an 
accumulation of fat. A decrease of haemoglobin (180) favors its 
accumulation. When demanded by the system, it appears to be 
discharged in a manner more or less mechanical. 

310. Urea (303). — The history of the early stages of urea has 
not yet been made plain. The antecedents of urea appear to be 
Jcreatin (C4H9N3O2), a constant constituent of muscle-juices, and 



NUTRITION. • 175 

leucin (C4H13NO2) and tyrosin (CgHi^NOg), two of the principal 
products of the decomposition of nitrogenous matter, especially in 
pancreatic digestion. Their change into urea ((NH2)2CO) may take 
place in the liver (271), the kidney (303), or the spleen ; but of the 
method of change we are yet ignorant. In the production of heat 
and other energy from the tissue-constituents, many intermediate 
products are formed. All the non-nitrogenous substances yield car- 
bonic acid and water, and the nitrogenous ultimately yield carbonic 
acid and water, uric acid, and urea. Urea is a crystallizable body, 
and is the characteristic ingredient of urine. It exists in the blood, 
and has been detected in the saliva and chyle. It contains all the 
nitrogen and part of the carbon and hydrogen of the proteids from 
which it is derived. 

311. Uric acid (C5H4N4O3) is normally present in the spleen, 
pancreas, and liver. It is found only in slight amounts in the 
urine of man. It is a product of proteid change, less oxidized 
than urea. It is not, however, an antecedent of urea. Like urea, 
it is eliminated by the kidneys. 

PRODUCTION OF HEAT AND ENERGY. 

312. In general terms, the human body is a machine for 
converting the latent energy stored in the foods into the 
active energy manifested in the heat and the work of the 
living body. Though the animal economy may combine 
simple compounds into complex compounds, as in the 
building up of complex tissues, yet in general it is en- 
gaged in reducing the complex compounds received as 
foods into the simpler compounds excreted as waste. In 
the process of breaking up of compounds, either by the 
union of oxygen with certain elements or the splitting of 
a complex compound into sim})ler ones, force and heat are 
evolved. Every ingredient of food contains a fixed amount 



312. "What is tho purpose of the hnninn body? Spenk of its 
general action. What is evolved in the process? "What does food 
contain ? 



176 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

of force or energy ; every one of the simpler compounds 
into which it may split up in the body also contains its 
smaller but yet definite amount of force ; and the difference 
between the force in the latter and that in the original sub- 
stance expresses the amount of force or energy which that 
substance contributes to the body. 

313. Manifestation of Force. — Plant-life, working 
under the influence of the sunlight, builds up the tree, 
which yields wood. If this wood be heated to a certain 
extent, as by rubbing two dry sticks together, the carbon 
of the wood unites with the oxygen of the air. The wood 
disappears, but heat, light, smoke, and carbonic acid gas 
and w^ater-vapor are produced. In this change, called 
oxidation, two forces, called heat and light, are made mani- 
fest to our senses. If similar bits of wood had been ex- 
posed to the atmosphere and allowed to decay, the oxygen 
of the air would have united more slowly with the carbon 
elements, not producing always carbonic acid at first, but 
certain intermediate products, which ultimately would be- 
come carbonic acid and water. In this latter case the heat 
and light would not be readily recognized by us, yet the 
amount of energy set free in either case would be the same. 
In both cases the complex carbon compound — wood — was 
oxidized ; in both cases carbonic acid and water were pro- 
duced ; and in both cases the same amount of energy or 
force was liberated. In the one case the energy was liber- 
ated in a brief space, and thus attracted the attention of 
the senses; in the other, the liberation was spread over 
such a length of time and so attenuated as not to attract 
the notice of the senses. 

313. What does the plant build up ? The results of quick oxidation ? 
Of slow oxidation (decay)? Of the results in either case? Differ- 
ences of the manifestations ? 



NUTRITION. 177 

314. The Production of Force iu the human body 
has been compared to the operations of the boiler and 
steam-engine. In the cold boiler, the water is quiescent 
and exerts no force, except pressure on the bottom and 
sides of the boiler. If the iron be heated, as by the burn- 
ing of wood under it, the heat-energy of the wood is trans- 
mitted to the liquid water, causing the latter to assume the 
form of steam. If now the steam be admitted into a cylin- 
der, with a piston and valves, its expansive power is changed 
into mechanical motion. As the steam may be used for 
heating, for propelling machinery, for drawing water, etc., 
so in the human body the energy set free by the oxidation 
of the materials of the food, or of certain materials in the 
tissues, may appear partly as heat or partly as motion, in 
the form of muscular work, electrical currents, tissue-con- 
struction, tissue-changes, etc. 

315. In the human body, the complex compounds of the tissues 
may, under oxidation, split at once into simple compounds, like 
water, urea, and carbonic acid, or they may give rise to interme- 
diate compounds, like lactic acid, kreatin, and tyrosin. The amount 
of force set free in either case will be the same, but the period of 
its evolution will be longer. The ultimate oxidation of the jiroteids 
produces urea (310) and carbonic acid and water ; of the fats, car- 
bonic acid and water; and of the carbo-hydrates, carbonic acid. 
During this process energy is made manifest. 

316. The INCOME of the body consists of C, H, 0, N, S, P, and 
the saline matters contained in the proteids, the f\its, carbo-hydrates, 
salts, and water of the food, and the uncombined oxygen and nitro- 
gen entering by the lungs, the skin, and the alimentary canal. The 
OUTCOME consists chiefly of carbonic acid and water, passing out 
by the lungs, skin, and alimentary canal ; the water and salts (the 
small amount of urea and uric acid may be nogleetod), by the 
skin ; and the water, salts, and, practically, all the nitrogen coni- 



314. Comparison of the hunmu body with tlio stcuni-engino? Spo:ik 
of steam-production iind its uses. Of enorgy- and hoat-prodiiotiou. 
m 



178 ANATOMY^ PHYSIOLOGY, AND HYGIENE. 

pounds, by the kidneys. Of these, the carbon, the nitrogen, and 
the uncombined oxygen are by far the most important factors. 
317. A LivixG Diet axd its Energy. — 





MOLESCHOTT. 


Pettenkofer. 


Eanke. 




Gh-ammes. 


Grumynes. 


Grammes. 


is . . 


. . 30 


148 


100 


. 


. . 84 


103 


100 


es, etc. 


. . 404 


378 


240 




. . 30 




25 


. 


. . 2800 




2600 



Fats 



Salts 

Water 

Moleschott's diet is derived from a comparison of a large number 
of public diets, and, as seen, the cheaper carbo-hydrates are used in 
place of the dearer fats. Pettenkofer's is calculated for soldiers, 
and hence has more of the stimulating proteids and less of the 
bulky starches. Ranke, a man weighing seventy-four kilogrammes 
(one hundred and sixty-three pounds), found himself in good health, 
neither gaining nor losing on his diet. For purposes of calcula- 
tion, Eanke's is best. When the ingredients of the first three items 
(the other two, salts and water, are left out of the calculation, as 
they contribute in themselves little or no force, but simply make 
the conditions for the action of the force-producers) are perfectly 
oxidized. Professor Frankland's data of combustion (Foster, p. 367) 
would make their energy equivalent to the following " gramme- 
degrees C. units of heat" and " metre-kilogrammes units of force." ^ 

Grammes. Gramme-degrees. Metre-kilogrammes. 



100 Proteid . . . . 

100 Fat 

240 Starch, etc. . . 


. 436,800 
. 906,900 
. 938,880 


185,000 
384,100 
397,680 


Total income . . 


. 2,282,580 


966,780 



1 A unit of heal is the amount of beat required to raise the temperature of a given 
weight of a given substance through a certain thermo/iietric space. The heat required 
to raise one kilogramme of water through 1° C. constitutes the French or " gramme- 
degree C. unit of beat." The heat required to raise one pound of water through 1° F. 
constitutes the English thermal unit. 

A unit of u-ork is the amount of force required to raise one kilogramme through one 
metre, which is called " metre-kilogramme unit." A unit of work (English) is the amount 
of force required to raise one pound weight through one foot — " foot-pound unit." 

One metre-kilogramme = 7.233 foot-pounds. 

One foot-pound = .138254 metre-kilogramme. 

One English thermal unit = (pound 1° F.) = 772 foot-pounds. 

One French thermal unit = (kilogramme 1° C.) = 424 metre-kilogrammes. 



NtJTRITION. 179 

318. The energy set free in the body appears in two forms, 
— HEAT and MECHANICAL LABOR. The normal expendi- 
ture for internal mechanical labor of an average adult is 
80,000 metre-kilogrammes. A good day^s work is put 
down at about 150,000 metre-kilogrammes. The external 
work, 70,000 metre-kilogrammes, is equivalent in walking 
to a twelve and one-half mile course for a man weighing 
one hundred and fifty pounds, or the raising of seventy- 
five pounds six feet high one hundred times an hour for 
ten hours. The normal energy-income of the adult body 
has been estimated in round numbers at 1,000,000 metre- 
kilogrammes (317). The normal expenditure in the form 
of heat has been determined by subtracting the mechanical 
labor-expenditure from the total energy-income. It is 
about 850,000 metre-kilogrammes. Hence from one-sixth 
to one-fifth of the total energy-income of the body is ex- 
pended as mechanical labor, and from four-fifths to five- 
sixths leaves the body as heat. The best steam-engines 
utilize in mechanical work only about one-tenth of the 
energy of the fuel employed in them. In this respect the 
body is an economical machine. 

319. The human body loses energy in the performance of 
muscular work, as in running, walking, climbing, etc., in 
all kinds of manual and bodily labor, in respiration, and 
in speech. This is equivalent, in a hard-working adult, to 
about 70,000 metre-kiloij^ramnies. The internal work of 
the body — the labor of the internal muscular apparatus, the 
labor in the molecular changes in the nervous, gland, and 



318. How does the energ-y appear? What is the value of the in- 
ternal work? Of the external work? Of the heat? AVliat of the 
economy of the human machine? 

319. How is energy expended ? Its value? AVhat of the internal 
work ? How is heat lost ? 



180 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

other tissues — appears as heat before it leaves the body. 
The body loses heat by conduction, removed directly by 
solids, fluids, or gases in contact with the body-surfaces, 
by radiation, thrown off into the surrounding atmosphere, 
after the manner of rays, and by heating the egesta, — the 
outgoing air, gases, water, and excrement. 

320. Heat-Production. — The larger part of the heat 
is due to the oxidation of carbon in the system. The chief 
sources of heat-production are seated in the muscles and 
the abdominal viscera, especially the liver, which contains 
nearly one-fourth of the blood. The blood of the hepatic 
veins in a dog was the warmest in the body (40.73° C), 
while that of the right heart was 37.7° C. Wherever 
changes in protoplasm are taking place, — in the brain, the 
nerve-centres, the glands, the heart-muscle, the general 
muscular system, — heat is generating. The heat is lost in 
about the following proportions (Helmholtz), by the various 
channels : 

In warming excrement and urine, 2.6 per cent. ; 
In warming expired air, 5.2 per cent. ; 
In evaporation of water of respiration, 14.7 per cent. ; 
In conduction and radiation and evaporation by the skin, 
77.5 per cent. 

321. Body-Heat. — In ordinary health, the temperature 
of man, as registered by a thermometer placed in the axilla, 
varies between 36.25° and 37.5° C. (97.25° and 99.5° F.). 
There is a diurnal variation of temperature, the maximum 
occurring from 9 A.M. to 6 p.m. The variation produced 

320. The chief cause of heat-production? What are the principal 
seats of heat-production ? Of heat-loss ? 

321. Temperature in health ? How modified ? Alcohol ? Exercise ? 
Climate? Study? Tasting? Temperature in disease ? Temperature- 
extremes ? 



NUTRITION. 181 

by the taking of food depends on the nature and the tem- 
perature of the food. Alcohol, as its earlier effect, appears 
to produce a fall of temperature. Exercise and ordinary 
variations of external temperature cause very slight changes. 
The temperature of the inhabitants of the tropics is practi- 
cally the same as that of those living in Arctic regions. Pro- 
longed study and other mental efforts cause a slight depres- 
sion. Fasting lowers the temperature, and in starvation the 
fall in temperature becomes very rapid in the last few days 
of life. The thermometer enables the physician to determine 
whether or not fever is present, and, at times, the nature 
of the fever. The fever temperature ranges from 37.8° to 
41.2° C. (100° to 106° F.). A temperature holding for 
hours above 41.6° C. (107° F.) is almost a certain forerunner 
of a fatal issue. In a case of cerebral rheumatism having 
a temperature of 43.4° C. (110° F.), the patient survived. 
Bernard places the lethal body- temperature of a mammal 
at 45° C. (114.8° F.). In extreme collapse, followed by 
recovery, the temperature rarely falls below 33° C. (92° F.). 
322. Regulation of Body-Heat. — The great heat- 
regulator is the skin (45). The blood circulating through 
the skin is cooled by heat-loss, due partly to the radiation 
and conduction from the skin, but much more to the evapor- 
ation of the water of perspiration. The larger the amount 
of blood flowing through the skin-vessels, the greater will 
be the heat-loss, and, as the amount of blood in the heat- 
producing areas (the muscles and the abdominal viscera) is 
at the same time in like degree lessened (320), less heat will 
be produced ; hence a fall of temperature will result. The 



322. How does the skin largely regulate the body-teniperatiire ? 
What controls the calibre of the arteries ? The conditions produced 
in cold weather? In warm weather? What may be a controlling 
factor ? 

16 



182 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

calibre of the vascular tubes of the heat-production and 
heat-loss areas is under vaso-motor influence (137). In 
cold weather this influence keeps the skin white, anaemic, 
and cold, in order to retain the bulk of the blood in the 
heat-production areas ; in warm weather, when the heat- 
production and heat-reception (from influences of the ex- 
ternal temperature) elevate the internal temperature, this 
influence contracts the internal vascular apparatus, enlarges 
the cutaneous blood-vessels, and the mass of the blood 
flows to the skin ; the latter becomes high-colored and 
glowing, and the activity of the perspiratory glands is en- 
couraged, followed by great heat-loss. The influence of 
an increase or decrease of heat-production through tissue- 
changes in its action on heat-regulation has not yet been 
well determined. There may, however, be a tissue-change- 
controlling mechanism, quite comparable to the vaso-motor 
mechanism, but it has not as yet been well established. 

323. In cold climates man uses padded cotton garments, 
many garments (having air-layers between each garment), 
fine-meshed woollens, and skins, to retain the body-heat 
and to retard heat-loss (50). In hot regions he diminishes 
heat-production by restricting his proteid diet, and encour- 
ages heat-loss by the use of larger amounts of liquid or 
fruit foods and the wearing of gauzy garments. In fever 
we endeavor to reduce heat-production by encouraging the 
action of the skin (sweating emetics) ; by diminishing tissue- 
change (alcohol, morphia, quinine, salicylic acid) ; by dimin- 
ishing the heart's action (digitalis, aconite, veratria) ; and 
at the same time to encourage heat-loss by tepid bathing, 
alcohol- and water-sponging, application of ice, internally 



823. What is a common-sense management in cold climes ? In hot 
climes? The Scientific management in fevers? 



NUTKITION. 183 

and externally, cold-sheet-pack, cold baths, etc., as well as 
the internal administration of perspiration-exciting drugs. 

324. ExcRETiOi^^. — The purpose of excretion is to rid 
the body of the compounds which are formed in the actions 
of living tissues. These compounds are given to the blood 
during its movements through the capillary areas (143). 
They are, for the most part, of no further use to the living 
economy. Most of them are injurious to healthy life, 
and, if not rapidly removed, produce evil, if not fatal, 
results. These materials are removed from the blood by 
the epithelia of certain organs and tissues. Some of them 
are eliminated at once, like carbonic acid and water, from 
the lungs and the skin ; others are kept in sacs for a time, 
to be later passed out, like the urea and excrement. 

325. Waste Products. — Broadly speaking, the waste 
products of the animal economy are urea, carbonic acid, 
salts, water, and excrement. 

326. The total daily excretion of carbonic acid in an average man 
was determined by Pettenkofer and Voit to be 800 grammes, or 406 
htres, containing 218.1 grammes (3365.8 grains) of carbon and 581.9 
grammes (8980 grains) of oxygen. The oxygen consumed during 
the determination was about 700 grammes (10,802 grains). Of 
these excretions, only 10 grammes (154.3 grains) were passed out 
by the skin. The quantity of oxygen consumed, and that of car- 
bonic acid given out, vary widely, the former ranging from 680 to 
1285 grammes, and the latter from 594 to 1072 grammes. 

327. The total daily average excretion of urea, as determined by 
Parkes, was 33.18 grammes (512 grains). The daily excretion of 
urea on an exclusively animal diet was found to be 53.14 grammes 
(820 grains); on a mixed diet, 32.40 grammes (500 grains); on a 
vegetable diet, 22.48 grammes (347 grains) ; and on a completely 
non-nitrogenous diet, 15.35 grammes (237 grains). The urea is 

324. What is the function of excretion ? Influence of waste matters 
in the system ? How are they removed ? 

325. Name the chief waste ])ri)ducts. 



184 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

formed largely from the food. The amount derived from the tissues 
is less than half the ordinary daily amount excreted. The nitro- 
genous waste of the body is almost entirely excreted by the kid- 
neys, traces only ordinarily escaping by the lungs and the skin. 

328. The total daily average excretion of salts in the urine, as 
determined by Parkes, is 37 grammes (570 grains). Of 100 parts 
of these salts, 53 parts are sulphates, 24 phosphates, 23 chlorides, 
and the rest salts of the organic acids. The chief base is soda, then 
potassa, ammonia, magnesia, lime, and traces of iron and silica. 
Most of these salts are derived directly fi'om the materials of the 
food, only a small portion arising in the tissue-changes of the twenty- 
four hours. By the shin, a small amount of chloride of sodium, and 
traces of other inorganic salts, are eliminated. By the rectum, con- 
siderable amounts of salts are passed out. 

329. The water eliminated from the body varies largely within 
the limits of health. The average daily amount appearing in the 
urine is 1500 grammes (53 ounces) ; exhaled from the skin, about 
742 grammes (30 ounces) ; and lost in respiration, 255 grammes 
(9 ounces). 

330. The excrement contains the indigestible and undigested con- 
stituents of the food, shreds of elastic tissue, cellulose from vege- 
table food and areolar tissue from animal food, fi'agments of muscle- 
fibre, fat-cells, and starch-grains. The amounts of these vary with 
the nature and the quantity of the food. From the digestive canal 
and glands the excrement receives mucus, fatty acids, a peculiar 
ferment, also excretin (a crystalline body containing sulphur), and 
salts, especially of magnesia. 

331. Summary. — The average man receives daily /ooc?s 
estimated at 1,000,000 metre-kilogrammes: 
Proteids in flesh, cheese, beans, etc. 
Fats in butter, lard, oils, etc. 
Carbo-hydrates in starches, sugars, fruits, etc. 
Salts in normal foods and condiments. 
Free oxygen via lungs and skin. 
Water in foods and drinks. 

331. Give the summary of man's daily food. What is evolved? 
What is excreted ? Prom whence excreted ? 



NUTRITION. 185 

Evolution of heat and force : 

Heat estimated at 850,000 metre-kilogrammes. 

Force estimated at 150,000 metre-kilogrammes. 
Average excretions : 

Carbonic acid via luDgs, skin, and alimentary canal. 

Urea via kidneys and skin. 

Water via kidneys, lungs, and skin. 

Waste via rectum and skin. 

Of the entire excreta, 32 per cent, pass off by the breath ; 
17 per cent, by the skin; 46.5 per cent, by the kidneys; 
4.5 per cent, by the alimentary canal. 

332. Thirst is a sensation referred to the tongue and 
palate. It is dependent on a general state of the system, 
as it is readily distinguished from dryness of the mouth. 
This general state of the system is caused by a deficiency 
of water in the blood. Thirst is soonest and most success- 
fully quenched by water, and especially by ice-water in 
small quantities at frequent intervals. The sensations of 
Appetite and Hunger seem to be dependent upon a 
general condition of the system. The former is agreeable, 
the latter painful. They are both referred to the stomach, 
but the presence or absence of food in the stomach does 
not wholly account for the sensation, since it is relieved 
by nutrient materials injected into the blood or the rectum. 
Hunger is not so readily relieved as thirst, but its demands 
can be more comfortably deferred than those of thirst. In 
healthy organism, appetite and hunger are the sensations 
which impel man to seek food, and, in general, they are 
safe guides as to the amount of food needed by the healthy 
system. 

332. Upon what doos thirst depend ? How "best satisfied ? Spoak 
of the sensations of appetite and hunger. To what referred? How 
satisfied? Their influence? 

10* 



186 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

333. Dietetics comprises the rules to be followed for 
preventing, relieving, or curing disease by means of food. 
Tendencies for health or for disease, tendencies for evil or 
for good, can be modified by diet. The bear at Giessen 
was gentle when fed on bread, but a few days' diet of flesh 
made him savage and dangerous. The boys in the reform- 
atory institutions of France were found to be improved 
physically, mentally, and morally by the more liberal diet 
secured them by M. Metz. * The energy of the American 
over the Asiatic workman is largely due to his more liberal 
diet. The diseases chargeable to food form the most numer- 
ous order arising from a single class of causes. Hygiene 
has been considered by some writers to be almost a branch 
of dietetics. 

334. Excess of Food. — If food is taken in too large 
quantities, the excess is not digested, and cannot be absorbed. 
It remains in the warm, moist, intestinal canal, undergoes 
chemical changes, putrefies, and forms large quantities of 
gases. As a result, irritation, pain, slight fever, vomiting, 
or diarrhoea may result. If the habit of over-eating is 
continued in moderation for long periods, dyspepsia and 
constipation ensue. Excess of proteid foods taken con- 
secutively leads to fulness and enlargement of the liver, to 
plethora of the system, to imperfect oxidation of food and 
tissue-elements, as shown in gout and certain kidney dis- 
eases. Excess of the starches tends to acidity and flatulence, 
and of the sugars and fats, joined with a deficiency of 
exercise, to a weakening of the muscular system. Excess 

333. What is understood by dietetics ? What is the influence of 
food on bears ? On boys ? On laborers ? On health ? 

334. What is the eiafect of an undigested excess? Of continued 
over-eating? Of excess of proteids ? Of starches ? Of sugars and 
fats? 



I^JUTRITION. 187 

may consist in taking too great a quantity at one time, in 
taking too large an amount in twenty -four hours, or in the 
too frequent taking of food. 

335. Deficiency of Food. — If the proteids be com- 
pletely withdrawn from the diet of a healthy man, after a 
few days a great loss of muscular strength, often mental 
weakness and want of decision, some feverishness, and in- 
digestion are noticed. This is succeeded by a falling ofF 
in the quality of the blood, and by general prostration. If 
the withdrawal of proteids be only partial, there is a lessen- 
ing of physical and mental activity, followed by a weak- 
ened condition of the system and a tendency to malarial 
affections, typhoid fever, and pneumonitis. The depriva- 
tion of both fat and starch produces illness in a few days. 
Under a diet containing no starch, but having fat in mod- 
erate quantities, the condition is sustained for a long time. 
The absence of all fat in food is not well borne. It has 
not yet been proved that starches can take the place of fat 
in nutrition. A deficiency of mineral ingredients produces 
marked results, as in rickets and bone-softening. 

336. Want of Food. — Shipwrecks and famines have 
afforded numerous examples of the complete deprivation 
of food, with its terrible history of pain over the region 
of the stomach, thirst, weakness of mind and body, sink- 
ing, intense debility, loss of voice, delirium, convulsions, 
and death. It is generally supposed that a healthy person, 
deprived of both solid and liquid food, would not live 
longer than ten days. 

335. Wliat is the effect of withdrawing; proteids from the diet? Of 
partial proteid deficiency? Of starch deficiency? Of fat deficiency? 
Of mineral deficiency ? Can starches replace fats ? 

336. What are the symptoms induced by total want of food ? How 
lonff can life be thus sustained? 



188 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Endurance.— On Marcli 2'2, 1880, Master Soma, aged fourteen years, with two com- 
panions, aged fifteen and seventeen respectively, left Tsuishicari, Yezo, to walk to Sap- 
poro, a distance of about twelve miles. Before setting out, they partook of a lunch of 
cold rice, pickled radish, and tea. Each took in his belt about two handfuls of rice, and 
Soma, in addition, enough ginger-relish for two meals for one person. That afternoon 
they lost the trail in a snow-storm, and were soon unable to proceed. Before going to 
sleep, they ate all the rice, most of the ginger, and some snow. They were lightly clad 
in cotton or bark tunics and leggings, wore open straw sandals, and had half a light 
blanket each. They had no materials to make a fire. That night the temperature, as 
registered at Sapporo, was 24° F. The next morning they could not walk, their extrem- 
ities having been frozen. Soma states that the eldest died on the sixth day and the other 
on the seventh day. During the period of exposure there was much snow, sleet, and 
winter rain, considerable wind, and very little clear sky during the day. Guided by the 
crows, the soldiers found Soma on April 19, twenty-eight days from the time he left 
Tsuishicari. 

He was brought to the Kaitakushi Hospital, at Sapporo, at 5 p.m. of that day, and came 
under my charge. He could not speak ; movements of the chest were scarcely to be 
detected ; no pulse at the wrist; impulse of the heart very feeble, and valve-sounds in- 
distinct. The brain-torpor was profound. The body was excessively emaciated, the ab- 
domen retracted, and the eyes deeply sunken in the orbits. There was no reflex action 
from the hands. The lower extremities were black and dead to the middle of the legs. 
On the 22d, he was able to articulate a few indistinct sounds. After the first ten days 
he made steady progress towards health, and later both stumps were amputated in the 
middle third of the legs. At the present writing (March, 1884), the young man is living 
at Kotoni, and enjoying good health. 

337. Amount of Food. — The diet of the child to the 
ninth or tenth year of age should be mainly milk, well- 
cooked oat-meal, decorticated wheat, simple puddings, and, 
occasionally, small amounts of roasted or boiled meats 
(231). The proportion of food required by a growing 
child is much greater per pound weight than is demanded 
by an adult (three times as much of carbonaceous and six 
times as much of nitrogenous), for the child has to form 
tissues and to build up its structures. 

338. After the tenth year, children may partake of the 
usual food of the family, tea, coffee, and sharp condiments 
excepted. At this time it will require half as much in 
quantity as an adult woman, and at fourteen years, quite 

837. What is the best diet for a child? 

338. What of the diet after the tenth year? For youth and for 
women ? For a man ? "What proportions ? 



NUTRITION. 189 

as much. In general, women require one-tenth less food 
than in-door workmen, and from one-fourth to one-third 
less than out-door workmen. A healthy, vigorous man 
consumes about nine hundred and seven grammes (two 
pounds) of dry solid matter daily, and of water (free and 
combined) 2494.8 grammes (5J pounds or pints). The 
relation of the carbonaceous (starches, sugars, fats) to the 
proteid (flesh, eggs, vegetable casein, etc.) is about 6 or 6J 
to 1 in a working diet. The best proportion for the com- 
mon wants of the adult human system is about 9 of fat, 
22 of proteids, and 69 of starches and sugars. 

338a. Ethyl-alcohol (241). The regular use of alcoholics 
by a well-fed person (all Americans, judged by the world's stand- 
ard, are well fed) is unnecessary, and it is actually harmful. Beer, 
wine, and spirits produce no desirable effects on the healthy body 
(245). The nutrient value of malt, bitters, acids, etc., of beer, ale, 
and wine, is quite small. The bulk of the food daily taken into 
the human body is used for force- and heat-production (312), and 
not for reconstruction (327). It has not been noticed that the 
alcohol consumed in the human body adds to a notable extent to 
the bulk of the body. The evidence that it is destroyed in the 
system (305a), and that in the oxidation (ethyl-alcohol: aldehyde: 
acetic acid : carbonic acid) heat — i. e. force — is evolved, is most 
positive [Dupr^, Anstie, Binz, Parkes). "The organism may sub- 
sist for a variable period on it exclusively" [Bartholoiv). In 
America, compared with meats, fish, bread, grains, etc., alcoholics 
as force-furnishers are not economical agents, and for this reason, 
if for no other, they should not be used. 

Recent researches [Dujardin-Beaumetz, 1S83) show that when 
the daily dose of pure ethyl-alcohol (taken in divided doses, well 
diluted) does not exceed one gramme (15.4 grains) for each kilo- 
gramme (2.2 pounds) of weight of body, it may be borne without 
inconvenience for a very long time, no perceptible lesions on the 
part of the digestive, hepatic, or nervous systems being produced. 
All in excess of this is injurious. 21ic regular use of aleohones is 
attended with danger (394, 407). 



CHAPTER XL 

THE NEEVOUS SYSTEM. 

Directions for Dissection. 

Remove the skin from the head and neck of the animal, as of a dog, cat, rat, or rabbit. 
Cut out and remove the lower jaw and its appendages. If possible, allow the parts to 
becume thoroughly frozen. With a cold saw, in the median line saw vertically between 
the nostrils, through the bones of the face, of the skull, and vertebfce as far as the fifth 
or sixth cervical vertebra. At this part saw in at right angles and remove one-half. 
Remove all splinters, loose tissue, etc. Such a section will expose the corresponding 
parts, as in Fig. 38. The parts thus brought Into view are the scalp, or the movable, 
hairy portions over the vertex; the periosteum of the cranial bones; the cranial bones, 
exhibiting in places two layers of compact bone, with an intermediate cancellated layer ; 
lining the interior of the cranial vault, a hard, firm, resisting membrane, the dura mater, 
which dips down from the vertex near the median line, forming a divisional fold be- 
tween the right and the left brain, the falx, and, projecting from the sides, forms a par- 
tition between the great and the little brain, the tentorium. Beneath the free edge of 
the falx is seen the cut surface of a band of white nerve-matter connecting the right 
with the left brain, the corpus callosum. Beneath the corpus callosum will be seen a right 
and a left depression, the lateral ventricles. 

With the handle of the scalpel loosen the cranial contents of one side from its case. 
Turn it out gradually, severing, as they present, the nerves leading to the nose, eye, etc, 
near the base, the tentorium, the posterior cranial and the spinal nerves. The larger mass, 
the cerehruin, is somewhat triangular, and piesents on its gray surface a number of con- 
volutions, -with depressions, called sulci, and beneath a number of white, projecting fibres, 
the cranial nerves. Behind the larger brain, separated from it by a deep depression, is a 
smaller mass, the cerebellum, whose cut surface presents a tree-like appearance, in gray 
material. Its outer surface is gray, like that of the cerebrum, but is arranged in more 
or less parallel ridges. Connecting the cerebrum and cerebellum and the medulla is a 
mass of nerve-substance, the pons, or "bridge." Leading back from this is the sphial 
cord, the enlargement of which, near the cerebellum and lying within the skull, is 
called the medulla oblongata. Leading from the inferior aspect of the cerebrum, pons, 
and medulla are seen numerous fibres, the cranial nerves, and from the cord a pair of 
nerves for each intervertebral space, the spinal nerves. 

The outer surface of the brain is smooth and moist. Dipping down into all the sulci 
will be seen a web-like membrane, abundantly provided with blood-vessels, the pia mater. 
The smooth, firm membrane lying in the cranium is the dura mater. 

In the frozen brain make a vertical incision with a sharp, thin-bladed knife parallel 
to the median surface, about half an inch from the falx border. This section shows that 
the convolutions and ridges are made up of gray nerve-matter, in the form of a much- 
puckered laj-er ; that the bulk of the cerebrum and cerebellum is composed of white 
190 



THE NERVOUS SYSTEM. 
A Fig. 72. 



191 




1. The cerebrum. 2, The ceroboll.nn. :?,:{, Spinal cord. 4, Tbe sciatic .umvo 
A. Apparatus of Smfll.-1, 2. Olfactory .u-rvo. r>. Appauati-s ok Vision -lo Ortic 



192 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

matter; tliat at the base of the brain are a number of gray ganglionic masses (optic 
tiialami, corpora striata, corpora quadrigemiua, etc.); that the pons is in connection 
with the cerebrum, cerebellum, and, through the medulla, with the cord ; that in the 
medulla there are gray masses; and that the cord has a gray central and a white outer 
layer. If a cross-section of the cord is made, a gray centre, with projecting horns and 
an upper and lower groove in the white matter, is presented. On the anterior under 
side of the cerebrum is seen projecting forward a small, elongated, globular mass, the 
olfactory lobe of that side. Just back of it are seen two round, white cords, commencing 
to cross each other, the commissure of the optic tracts. 

The skull is seen to be arched above, the under side of the arch having a uniform 
surface ; below, it presents depressions, projections, and numerous openings. The large 
opening on the posterior part of the skull affords passage for the cord and blood-vessels, 
and is called the occipital foramen. The other openings serve for the entrance of arteries 
and outlets for the cranial nerves and the veins. In animals, at birth, the bones of the 
cranial arch are frequently cartilaginous, but those at the base are always ossified at this 
stage of development. 

Remove the skin from the neck and thorax and from the foro-limb of the opposite 
side from which half the skull was removed. Place the animal on its back. Cut the 
■pectoral muscles (the muscles which hold the limb to the trunk) close to their insertion 
in the humerus, and allow the limb to fall from the trunk. Remove the loose cellular 
tissue between the limb and the neck-back region, and the many white cords of the 
brachial nerve plexus will be exposed. Carefully remove all loose areolar and muscular 
tissue. It is advisable to preserve the arteries in position. Trace the nerves to the inter- 
vertebral places of exit. Number the vertebrae from the head. By the removal of the 
cellular tissue, the dissecting out of some and the cutting of other muscles, the nerve 
and the neighboring arteries can be traced in their distribution down the limb. Observe 
that the nerve-trunks are placed on the inner side of the limb, that they lie between 
muscles and are deeply embedded in areolar tissue, and that they are distributed to all 
tissues of the limbs, including the membranes of the joints. In the neck dissect out the 
pneumogastric truuk. Trace its branches to the different parts of the respiratory tract, to 
the heart, and to the stomach. 

Biisection of the remainder of the animal : 

Open the thorax, as directed in Chapter V. 

Dissect out and trace the branches of the arch of the aorta. 

Examine the heart. (See paragraph 89.) 

Dissect the respiratory tract, as directed in Chapter VI. 

Dissect the abdominal and pelvic organs, as directed in Chapter VIII. 

Dissect the motor apparatus, as directed in Chapter XIV. 

Hardening of the Brain.— Vass 60 per cent, alcohol through the vessels of the brain, and 
irrigate the ventricles with the same. Place the mass in .55 per cent, alcohol, and grad- 
ually increase the strength up to 95 per cent. Thus hardened, it can be better handled 
and more successfully dissected. Small cubes of different ])arts of the brain and sections 
of the cord may be placed in alcohol No. 1, to prepare for microscopic work. Make a 
number of transverse sections of the hardened cervical spinal cord. Endeavor to secure 
sections passing through the nerve-roots ; stain with haematoxylon and clear with car- 
bolic acid. Note the anterior and posterior fissures ; the pia mater of the cord ; the ante- 
rior and posterior roots ; the anterior, posterior, and lateral columns of white matter; the 
gray matter, with its horns ; the central canal ; the commissures, etc. Study the fibres in 
hardened specimens, and the cells and fibres in teased fresh specimens. 



THE NERVOUS SYSTEM. 



193 



The Head. 

339. The framework of the head is made up of twenty- 
two bones, of which eight enter into the formation of the 
skull, or brain-case, and fourteen into that of the face. 
(Table of bones, Chapter III.) * 



Fig. 73. 




Fig. 73. Bones OF THE Head.— 1, Frontal bone. 2, Parietal bone. 3, Temporal bone. 
4, Occipital bone. 5, Nasal bone. 6, Malar bone. 7, Upper jaw. 8, Os unguis. 9, Lower 
jaw (maxilla). 

The bones of the face are irregular in form, and, w^ith 
the exception of the lower jaw, are closely and firmly 
joined to one another and to the adjacent bones of the skull. 
Beneath the frontal bone are the two deep quadrangular 
cavities, called the orbits, wdiicli contain the eyeballs, the 
tear-apparatus, and the protective organs of the eyes; in 



339. "What of the facial hones? Of the orhits and thoir contents? 
Of the nasal region ? "What are located in other depressions ? 
I n 17 



194 



ANATOMY, 



Fig. 74. 



the middle of the face, projecting upward between the 
inner walls of the orbits, are the two deep narrow channels 
containing the organs of smell, and in the lower part of 
the same, the broad nasal passages. The nasal passages 

(429) are separated from the 
cavity of the mouth by the 
hard palate. In the depres- 
sions and small cavities of 
the face are located glands, 
nerves, and blood-vessels. 

340. The eight bones of 
the adult skull are firmly 
joined together. The bones 
forming the vault of the skull 
(the frontal, the two parietals, 
and the occipital) are united 
together by the serrated form 
of union called the suture 
(Fig. 119). The bones of 
the vault are made up of an 
outer layer of tough, resisting 
bone, an intermediate layer 
of cancellated bone, and an 
internal layer of brittle bone. 
The inner surface of the 
vault is smooth, and shows channelled places for the pas- 
sage of blood-vessels. The bones of the base of the skull 
{occipital, sphenoid, frontal, temporal, and ethmoid) are 
crowded firmly in apposition. In the interior, the base 
has many elevations and depressions and numerous holes. 




Fig. 74. Facial view of the Head. — 
1, 2, 3, The liones of the skull. 4, The 
zj'gomatic process of the temporal bone. 
5, The malar (cheek) hone. 6, The supe- 
rior maxillarj' bone (upper jaw). 7, The 
Tomer, that separates the cavities of the 
nose. 8, The inferior maxillary bone 
(lower jaw). 9, The cavity for the eye. 
10, The teeth. 



340. How many bones in the skull? What of the vault? 
sutures? Of bony plates ? Of the base ? Of the openings? 



Of 



THE NERVOUS SYSTEM. 



195 



The former correspond to the form of the brain, and the 

latter serve for the passage of nerves and blood-vessels. 

The skull contains and protects the ^ 

- \ Fig. 75. 

brain J its nerves and membranes. 

341. In the arrangement of the skull for 
the protection of the brain, the oval form 
(the form best adapted to resist pressure 
equally applied on all sides) ; the thick- 
ened base, where the most important part 
of the brain lies; the strong and narrow 
prominences, both in front and back, where 
most exposed to violence; the tough and 
hard plates, to resist the penetration of 
sharp substances; the intervening spongy- 
layer, to diminish vibrations ; the separate 
bones and the serrated unions of the exter- 
nal plates, also to lessen shocks ; the simple 
contact of plane edges in the internal vit- 
reous plate, where zigzag edges would be 
easily broken ; the projections, depressions, 
and apertures for the safe passage of nerves 
and blood-vessels, — all combine to accom- 
plish the one object, protection. 

342. The Vertebral Column 
(149) is made up of a series of bones, 
called vertebrce. Each vertebra con- 
sists of a solid part (body), of an 
open ring {foramen), and of three 
major projections (processes). (Fig. 
76.) There are twenty-four mova- 
ble vertebrae, — seven cervical, twelve 
dorsal, and five lumbar. The sac- 
rum, in the embryonic stage, is made up of live vortebra% 
and the coccyx of four (247). 

343. The Spinal Canal is formed, in the natural state, 



Fig. 75. A Section of the 
Br.\in .\nd Spinal Column. 
— 1, Tlio cerebrum. 2, The 
cerebollum. 3, The uiedulla 
oblongata. 4, 4, The spinal 
cord in its canal. 



196 



by the succession of these rings of bone. It extends from 
the back part of the base of the skull nearly to the lower 
end of the vertebral column. The cranial cavity and the 
spinal canal communicate through the occipital foramen. 
This canal contains the spinal cord (364), its membranes 
and vessels. Its intervertebral openings give exit to thirty- 
one pairs of nerves. 



Fig. 76. 



Fig. 77. 





Fig. 76. A Vertebra of the Neck.— 1, The body. 2, The foramen. 4, The spinous 
process, cleft at its extremitj'. 5, The transverse process. 7, The inferior articulating 
process. 8, The su])erior articulating process. 

Fig. 77. A Lumbar Vertebra. — 1, The cartilaginous substance that connects the 
bodies of the vertebrse. 2, The body. 3, The spinous process. 4, 4, The transverse 
processes. 5, 5, The articulating processes. 7, The foramen. 

THE NEEVOUS SYSTEM. 

344. This system in man includes the cerebrospinal sys- 
tem and the sympathetic system. The former is composed 
of the brain and spinal cord and the nerves leading from 
them to the skin, muscles, and organs of the body. The 
sympathetic system is made up of ganglia, connecting 
fibres, and nerves. Its nerves are distributed to the vis- 



343. What is the extent of the spinal canal ? What is found in the 
canal ? 

344. What does the nervous system include? What is embraced 
in the former ? In the latter ? To what are the nerves of the latter 
distributed? 



THE NERVOUS SYSTEM. 197 

cera and to the vascular system, and also are in connection 
with the cerebro-spinal system. 

345. Nerve- Fibres and Nerve-Centres. — The 
nerves are made up of white nerve-fibres (78), bound to- 
gether by traces of delicate areolar tissue. The nerve- 
centres (ganglia) are composed of gray nerve- or ganglionic 
cells (80) and white nerve-fibres. 

346. The Functions of the Nervous System are — 
(1) sensation^ common, as of the skin, and special, as of the 
eye, the ear, etc. ; (2) the regulation of all the motions of 
the animal body ; (3) the manifestation through its centres 
of thought, will, intelligence, and the faculty of language ; 
(4) the exercise of a controlling influence over the nutritive, 
vascular, and other mechanisms, the proper working of 
which is essential to the continuance of life. 

347. The fiinction of the nervous system is innervation. It re- 
ceives impressions and transmits impulses. Its centres receive, 
record, and act upon impulses, and originate new impulses. The 
reception, origination, and transmission of nervous impulses are 
necessary for the proper maintenance of life and continuance of 
the functions of the various organs. Through the action of the 
end-organs of the nerves, of the nerve-fibres, and of the great cen- 
tres, the mind of man is made conscious of external phenomena 
and of his relation thereto. Through the action of centres in the 
brain, he is made conscious of himself and of his own mental 
actions. 

348. The nerves only transmit impulses. All other 
nerve-tissue functions are performed by the cells of the 
centres (83). If a ray of colored light enters the eye, the 

345. Of what are nerve-fibres composed? Nerve-centres? 

346. What are the functions of the nervous' system ? 

347. Give a function of the nervous system. Nervous impulses. 

348. What do the fibres do? The cells? How does sensation 
occur? How motion ? How brain-action ? 

17* 



198 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

end-orgaii of the nerve of sight (retina) receives a peculiar 
impression, an impulse is transmitted to the receiving 
centre in the brain, and the activity becomes manifest as a 
state of consciousness, — a sensation. A brain-centre may 
originate an impulse, which, being sent to a certain muscle, 
manifests its activity as motion. A brain-centre may origi- 
nate an impulse, which, being transmitted to another centre, 
manifests its activity as an ideaj an emotion j or a mental 
sensatio7i. 

349. Impulses. — The power of initiating vital impulses, inde- 
pendent of any immediate disturbing event or stimulus from with- 
out, is one of the fundamental properties of protoplasm (9). The 
power of initiating nervous impulses is a distinctive function of 
the ganglionic nerve-cells (84). The impulse is known by its ac- 
tion. Its nature appears to be that of an explosive discharge. The 
building up, the storage, and the setting free of the impulse appear 
to demand the use of much energy. The continued setting free of 
the explosive is followed by a sensation of weariness, a desire for a 
period of rest and recuperation. This is w^ell seen in the deep 
sleep following the rapid and exhausting impulse-discharges of an 
epileptic attack. 

THE CEREBRO-SPINAL SYSTEM. 

350. The entire Brain, or Encephalon, is chiefly made 
up of two parts, — an anterior upper part, called the cere- 
brum, and a smaller part, called the cerebellum^ or little 
brain. Besides these, there are the connecting parts, called 
the peduncles, the pons, and the medulla. They are all 
seated within the skull. 

351. The entire human brain weighs, on an average, in the adult 
female, 1262 grammes (44^ ounces), and in the adult male, 1410.36 
granxmes (49| ounces). In extreme cases, the brain has attained 

350. Of what is the brain composed? Where situated? What 
connecting parts ? 



THE NERVOUS SYSTEM. 199 

the weight of 2012 grammes (74.8 ounces). In an idiot boy it 
weighed as low as 241 grammes (8^ ounces), and in a female idiot 
forty-two years of age, 283.5 grammes (10 ounces). The maxi- 
mum average in the European is observed between the thirtieth 
and fortieth years. In a European white, a brain must weigh at 
least 975 grammes (34.39 ounces) in the female, and 1133 grammes 
(39.96 ounces) in the male, in order to be capable of performing its 
functions. Professor Owen found the weight of the brain of a 
gorilla to be 425 grammes (15 ounces). In a healthy body the 
average proportion to the entire weight is as 1 to 41. 

WEIGHT OF THE BRAIN IN SOME EMINENT MEN. 

Name. Age. Profession. Weight of Brain. 

Grammes. Ounces. 

Turgeneff 65 Author. 2012.00 (74.83) 

Cuvier 63 Naturalist. 1829.96 (64.54) 

Byron 36 Poet. 1807.00 (63.73) 

Lejeune Dirichlet ... .54 Mathematician. 1520.00 (53.61) 

Agassiz 66 Naturalist. 1513.97 (53.40) 

Fuchs 52 Pathologist. 1499.00 (52.87) 

Gauss 78 Mathematician. 1492.00 (52.62) 

Dupuytren 58 Surgeon. 1436.00 (50.65) 

Hermann 51 Philologist, 1358.00 (47.90) 

Haussmann 77 Mineralogist. 1226.00 (43.24) 

The brain increases, other things remaining the same, in proportion to the vascular 
activity of which it is the seat. This is the reason that the brains of certain criminals 
and lunatics have been found so large. In most cases, the physiological activity, of 
which intelligence is the result, has the most influence on brain-development. 

352. The Cerebrum consists of two lateral hemispheres 
united by a thick, broad band of white nervous tissue (cor- 
pus caUosum). They are sustained below by stalks of ner- 
vous substance, called peduncles. The whole of its free 
surface is composed of a layer of gray nervous matter. 
This layer, about one-fifth of an inch in thickness, is 
moulded into numerous tortuous and complicated eleva- 
tions, called convolutions. This layer is made up of nerve- 
cells (80), with numerous fine white fibres. The bulk of 



352. Describe the cerebrum. The convolutions. 



200 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



the cerebrum is composed of white nerve-fibres, which 
fibres ultimately connect with the fibres in the gray layer. 

353. Within the hemispheres and below the corpus callosum are 
certain cavities, called ventricles. By the old anatomists these were 
held to be the residence of the '^ animal spirits." Lying in front 




Fig. 78 represents a Convoluted Cerebral Hemisphere.— a, a, The scalp turned 
down, h, b, h, The cut edge of the bones of the skull, c, The external strong membrane 
of the brain (dura mater), suspended by a hook, d, The left hemisphere of the brain. 

of the peduncles, but projecting into the lateral ventricles, are two 
masses of gray matter, the corpora striata in front and the optic 
thalami behind. Resting on the back part of the peduncles are four 
small eminences, called the corpora quadrigemina (Fig. 80, 1, Fig. 
81, 28). On the under side of the front lobe of the cerebrum are 
seen two small, ovoid masses of gray matter, the olfactory lobes. 

354. The initiative acts of thought pass through the gray sub- 
stance ; consequently the greater the amount of gray substance, and 
of surface upon which it can be developed in a continuous layer, 



THE NERVOUS SYSTEM. 201 

the more power the truly intellectual phenomena acquire. Hence 
the gray surface is folded and contorted so as to increase its extent. 
The arrangement of the swellings is definite. The fundamental 
convolutions are constant throughout the human species ; the sec- 
ondary parts, or folds, exhibit variations. The brain of the fcetus 

Fig. 79. 




Fig. 79. Diagram of Human Brain, in Vertical Section, showing the situation of 
the different ganglia and the course of the fibres.— 1, Olfactory ganglion. 2, Hemisphere. 
3, Corpus striatum. 4, Optic thalamus. 5, Tuhercula quadrigemina. 6, Cerebellum. 
7, Ganglion of tuber annulare. 8, Ganglion of medulla oblongata. 

at the beginning is smooth ; at the seventh month the convolutions 
are simple; at birth the folds are simple; hxter, the complicated 
folds are rounded out. The convolutions become enlarged and 
more complex as age advances, in proportion to the activity of tlie 
organ. Large and simple convolutions are a sign of idiocy ; small 
convolutions, with numerous foldings, are a sign of intellectual 
capacity. 

FUNCTIONS OF THE SUPERIOR PARTS OF THE BRAIN. 

355. If the cerebral lobes be removed from a frog, he 
seems to possess no volition. \^ his flanks be now i^ently 
stroked, he will croak, and the croaks will follow rcg-ularly 



355. What effect has the rcmoviil of the cerebral lobes on a frog? 
What occurs when the lobes avo intnct? AVhat is volition? 



202 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

after each stroke. He can swim, can keep his balance on 
a tilted board, will avoid places which are dimly lighted, 
can pass from the water to a floating stick, can eat, drink, 

Fig. 80. 




wiJUfev. 



.aa 




Fig. 80 {LeuJy). CoEPt's Callosum removed and Cerebellum cut open in Median 
Line. — 1, Quadrigeminal body. 3, Superior peduncle of the cerebellum. 4, Superior 
portion of the middle peduncle. 8, The cerebellum. 15, Thalamus. 16, Hemispheres 
of the cerebellum. 17, Dentated body. 21, Corpus striatum. 22, Fifth ventricle between 
the layers of the pellucid septum. 



and sleep well ; but he does not move unless stimulated 
from without. If the flanks of a normal frog be stroked, 
he may or he may not croak. His actions cannot be predi- 
cated. He has cerebral lobes. He possesses volition. The 



THE NERVOUS SYSTEM. 203 

mutilated frog is a machine, and nothing more ; the other 
is a machine governed and checked by a ruling will. 

356. When the cerebral lobes are removed from a bird, 
its movements appear like those of a clumsy, stupid, 
drowsy bird. Left alone, it will remain quiet for a long 
time; placed on its back, it will regain its feet; thrown 
into the air, it will fly with precision and in a definite 
direction ; disturbed, it will shift its position ; kept alive 
for some time, it cleans its feathers : in short, it appears to 
be in full possession of a bird's powers, except satisfactory 
indications of intelligence and definite will-power. 

357. Functions of the Cerebrum. — In the human 
brain the impulses which cause the varied movements of 
the body, as walking, grasping, balancing, etc., arise in the 
pons, the medulla, and the parts of the hinder brain. In 
the nerve-cells of the convolutions arise the impulses which 
set in motion, retard, or stop the impulses arising in the 
inferior centres of the brain. The nerve-cells of the con- 
volutions are the seat of volition, of consciousness, of edu- 
cated intelligence, and of the faculty of language. These 
powers are injured or lost from experimental sections, dis- 
ease, or destruction of these parts. 

358. Functions of the Convolutions. — Men have lost by 
accident large masses of cerebral material upon one side, and, after 
recovery from their wounds, have suffered little or no impairment 
of the mental functions. The healthy brain-tissue is not sensitive 
to ordinary irritation, as pricking, cutting, or mild electric currents. 
A series of careful experiments by Hitzig, Fritsch, Ferrier, and 
others have shown that there is a connection between the faradic- 

356. What of the action of a bird which has lost its cerebral lobes ? 
What faculties are lost? 

357. Where do " movement-impulses" arise? Where is the seat of 
" originating impulses"? Of what are the oonvohition-eells the seat? 
What proof? 



204 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

electric stimulation of certain areas of the brain-surface and certain 
definite muscular movements. These experiments make it quite 
certain that there is a localization of function in the brain-surface. 
It has been noticed that aphasia (the loss of articulate speech) is 
almost always associated with disease of the hinder portion of the 
third convolution. In a vast majority of cases the disease is on the 
left side of the brain. In microcep hales, who have never been able 
to learn to speak, the third frontal convolution has been found 
atrophied. Hence it is inferred that in these convolutions — not in 
the muscles, or in the motor nerves, or in the motor centres of the 
brain — the fundamental phenomenon of articulate sj)eech is located 
(495). 

In 1877, when house-surgeon at Boston City Hospital, I had under my charge a man 
suffering from compound comminuted fracture of the left vault. Eleven pieces of bone 
were removed, leaving a hole about one and a half inches in diameter. The man lived 
eighty-three days, retaining his mental faculties, speech, and motion up to the last week. 
After the primary inflammation had subsided, the cerebral tumor was insensible to gentle 
manipulation. During waking hours it was gorged with blood and projected ; during 
deep sleep it became pale, and partially sank into the cranial cavity. A laborer in New 
Hampshire was tamping a charge of powder into a rock, when, by a premature discharge, 
the rod (three feet seven inches long, one and one-fourth inches in diameter, and weigh- 
ing about thirteen pounds) was driven into the left side of the face, near the angle of the 
jaw, passed through the front part of the cranial cavity, and emerged through the frontal 
bone in the median line, driving bone and brain before it. The man became delirious 
and comatose, but subsequently recovered, although with loss of sight in the left eye. 
Later, this man drove coach in Chili for my acquaintance, Mr. J. Allen, the manager of 
the American Line. Twelve years after the accident the man lost his life in California. 
The skull is now in the Harvai'd University Medical Department Museum. Fischer re- 
ports {Deutsche Zeit. fur Chir., 1883) the case of a carbine iron ramrod entering the chest 
to the right of the fourth dorsal vertebra, passing through the neck, the base of the skull, 
and the brain, and projecting thirty centimetres out of the left side of the head. The 
ramrod was driven back into the neck by blows of a hammer, and removed. The patient 
recovered, losing sight in the right eye, however. 

359. Bilateral Action. — In general, both cerebral hemispheres 
probably act together, each part being respectively associated by its 
nerve-connections. One hemisphere has been shown to be sufficient 
for the exhibition of all the mental functions, and to exert a due 
influence on the body. It is possible that the right and the left 
brain may be at the same time engaged in different trains of ideas. 
Why are most persons right-handed f Why is the faculty of lan- 
guage more often exercised from the left side ? According to M. 
Broca, the left hemisphere, which presides over the movements of 
the right side of the body, owing to the decussation (365) of the 
nerves near their origin, has, from the first, a greater amount of 



THE NERVOUS SYSTEM. 205 

activity. This primary excess of activity extends to all the func- 
tions of which this hemisphere is the seat, and notably to that of 
articulation. There are persons who originally, or after a disease in 
the left hemisphere, siDcak with their right brain ; in the same way, 
there are some who were originally left-handed, and others who 
have become left-handed in consequence of loss of, or inability to 
use, the right hand. 

360. Eapidity of Cerebral Action. — To determine this, the 
person experimented upon makes a signal as soon as he perceives 
a stimulus. The stimulus used may be a sound, a flash of light, or 
an induction (electric) shock. The moment of applying the stimu- 
lus and the moment of making the signal, as by pressing on an 
electric button, are recorded on a paper ribbon moved by clock- 
work at a known uniform speed. The interval between the two 
points is carefully measured, and the fraction of time accurately 
calculated. This interval of time is called the " reaction period." 
The length of this period varies in every person according to the 
nature and disposition of the stimulated end-organ. 

361. The "reaction period" of astronomers has long been known. 
It is known that two men watching the same star under the same 
circumstances are not able to record its transit over a line at the 
same moment. Between the years 1814 and 1834 the "reaction 
period" of Struve was from .04 to 1.08 seconds longer than that 
of Bessel. It is known by astronomers that the individual "reac- 
tion period" varies, and that they are not always able to record the 
contact of stars equally sharply. This has given rise to the so-called 
" personal equation" of observers. Bonders has determined the re- 
duced " reaction period" to be — feeling one-seventh, hearing one- 
sixth, and sight one-fifth of a second. Exner has shown that it 
takes an intelligent person less than one-tenth of a second to per- 
ceive and to will. 

862. Functions of the Superior Ganglia. — The corpora 
striata and the optic thalnmi, often called the "basal ganglia," are 
the great means of communication between the cerebral hemi- 
spheres on the one hand and the peduncles on tlie other. As the 
great mass of the peduncular fibres connect in an indirect manner 
with the external gray layer through the basal gangli^i (a few fibres 
are found, however, to pass directly), these nerve-masses appear to 
act as " middle-men" between the cerebral convolutions and the 

18 



206 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



rest of the brain. It cannot at present be stated definitely what is 
the nature of the mediation which either body respectively effects. 
Injuries or lesions of these ganglia of one side cause loss of motion 
and of sensation on the opposite side of the face and body. When 
both are injured, the will is unable to cause action below the gan- 
glia, or the consciousness to be influenced by impulses from below. 

Fig. 81. 




Fig. 81 {Leidtj). Section of the Brain along the Great Longitudinal Fissure.— 
1, Medulla oblongata. 2, Pons. 3, Crus of the cerebrum. 4, Arborescent appearance in 
section of the cerebellum. 5, Left hemisphere of the cerebellum. 6, Inner surface of the 
left hemisphere of the cerebellum, 7, Corpus callosum. 8, Pellucid septum. 9, Fornix. 
10, Anterior crus of the fornix. 19, Foramen of communication between the third and 
lateral ventricles. 20, Optic nerve. 24, Oculo-motor nerve. 26, Fourth ventricle. 28, 
Quadrigeminal body. 29, Entrance from the third to the fourth ventricle. 30, 31, 32, 
Anterior, middle, and posterior lobes of the cerebrum. 

In the vicinity of the front eminences of the corpora quadrigemina 
are seated the centres for the co-ordination of the movements of the 
eyeballs (466), and for the contraction of the pupil (459). These 
two centres work together. If the eminences of one side are re- 
moved, the animal loses sight on the same side. All experiments 
indicate that these nervous eminences are the centres of sight (462). 

The olfactory lobes are concerned in the sense of smell. Odorous 
particles present in the air in the upper nasal chambers, acting on 



THE NERVOUS SYSTEM. 207 

the epithelium of these lobes, produce sensory impulses, which, 
ascending to the brain, give rise to the sensations of smell (430). 

Fig. 82. Fig. 83. 





Fig. 82. (Dalton). Medulla Oblongata of Human Brain, anterior view. — 1, 1, Anterior 
pyramids. 2, 2, Olivary bodies. 3,. 3, Restiform bodies. 4, Decussation of the anterior 
columns. The medulla oblongata is seen terminated above by the transverse fibres of 
the pons Varolii. 

Fig. 83. Anterior View of the Brain and Spinal Cord.— 1, 1, Hemispheres of the 
cerebrum. 3, 3, Cerebellum. 4, Olfactory nerve. 5, Optic nerve. 7, Third pair of 
nerves. 8, Pons. 9, Fourth pair of nerves. 10, Lower portion of the medulla oblongata. 
11, Spinal cord. 

363. The Cerebellum, or little brain, is situated be- 
neath the back lobes of the cerebrum. It is made up of 
gray nerve-matter without and white matter within. Its 
surface is crossed by numerous furrows, which vary in 
depth. A slight notch in front and behind marks it off 
into two hemispheres. A vertical section brings tlie tree- 
like arrangement of the white matter into view. 

364. The Spinal Cord is tlie cylindrical long mass of 



363. The cerebellum ? Location? Appcaranco? Divisions? Ap- 
pearance of interior? 

364. The spinal cord? Location? Extent? EnlargiMueuts? 
Speak of the color and the fissures. 



208 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



nerve-matter contained in the spinal canal (343). It ex- 
tends from the pons to the first lumbar vertebra, from 
whence it is continued as gray filaments into the sacrum. 



Fig. 84. 




Fia. 8i (Leirhj). Base of the Brain.— 1, Anterioi .-_.,.,,., „, the cerebrum. 2, Middle 
lobes. 3, Posterior lobes. 4, 5, Anterior and posterior extremities of the great longi- 
tudinal fissure. 11, Crura of the cerebrum. 12, Pons. 13, Medulla oblongata. 14, Pyram- 
idal bodies. 14*, Decussation. 15, Olivary body. 16, Restiform body. 17, Hemispheres 
of the cerebellum. 19, Cms of the cerebellum. 20, Pneumogastric lobule of the cere- 
bellum. 21, Fissure which accommodates the olfactory (1) nerve (22). 23, Bulb of the 
olfactory nerve. 24, Optic commissure. 25, Oculo-motor (3) nerve. 26, Pathetic (4) nerve. 
27, Trifacial (5) nerve. 28, Abducent (6) nerve. 29, Facial (7) nerve. 30, Auditory (8) 
nerve. 31, Glosso-pharyngeal (9) nerve. 32, Pneumogastric (10) nerve. 33, Accessory (11) 
nerve. 34, Hypoglossal (12) nerve. 

At the lower part of the neck and in the lumbar region 
it presents enlargements. From these enlargements the 



1 



THE NERVOUS SYSTEM. 209 

nerves of the extremities branch off. Many nerves from 
the external parts of the body terminate in the cord. The 
cord does not fill the canal, but is held in place by its mem- 
branes. It is white without and gray within, the reverse 
of which is seen in the brain. It is divided by front and 
rear fissures into a right and a left portion. 

365. The Medulla Oblongata is the upper enlarged 
part of the spinal cord. It extends from the upper border 
of the first vertebra to the pons. It is divided by fissures 
into a right and a left portion, and the latter by grooves into 
four columns. Many of the fibres of the anterior column 
(motor in function) cross over and make connection with 
the cerebral hemisphere of the opposite side. This is the 
decussation of the anterior columns of the cord. Special 
deposits of gray matter are found in the interior (Fig. 79). 

366. The Pons, or " bridge,'^ is the bond of union of the 
various parts of the brain connecting the cerebrum above, 
the medulla, and, through it, the spinal cord below, and the 
cerebellum behind (Fig. 84, 12). 

367. Membranes of the Cerebro-Spinal System. 
— The skull and spinal canal are lined by a continuous tough 
membrane called the dura mater. This acts in the skull as 
a kind of periosteum (16), and in both portions it smooths 
off the bony roughnesses. The inner surface of the dura 
mater is in contact with a thin membrane, the arachnoid. 
The jpia mater is a very vascular membrane, w^hich dips into 
all the depressions of the brain and cord, and in the nour- 
ishment of which it assists. 

365. What of tho medulla oblons^fita? Extent? Fissures? AVhat 
is the decussation ? Gray matter? 

366. Speak of the pons. 

367. What is the dura mater? For what does it serve? What of 
the arachnoid? Of the pia mater? 

o 18* 



210 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

368. Between the arachnoid and the cord is a considerable space, 
which is called the sub-arachnoidean space. It is largest at the lower 
part of the canal. It communicates with the ventricles of the brain, 
and contains an abundant serous fluid. This secretion is suflicient 
in amount to expand the arachnoid and to fill completely the inte- 
rior of the dura mater. This fluid forms a water-bed for the delicate 
structures of the cord and the internal ganglia of the brain. When 
the blood-pressure in the brain suddenly becomes too great or too 
small, the fluid is forced out of the ventricles into the spinal por- 
tion, or vice versa. Thus it regulates the degree of pressure on the 
brain and spinal-cord centres. When this fluid is suddenly with- 
drawn, great brain-disturbance ensues. 

369. Functions of the Inferior Parts of the 
Brain. — Experiments and disease-action show that the 
nervous machinery required for the execution of bodily 
movements (both visceral and skeletal) is present after 
complete removal of the cerebral hemispheres. When the 
brain is reduced to the corpora quadrigemina and cere- 
bellum, with the peduncles and the pons, the mammal is 
able to execute all ordinary movements. When the parts 
between the hemispheres and the medulla are removed {i.e,j 
the pons, peduncles, and ganglia), a large number of com- 
plex movements are no longer executed : the animal can 
no longer balance itself; it lies helpless on its side, and 
can only perform simple movements when disturbed. If 
the medulla of a mammal is removed or destroyed, death 
ensues. 

370. In the inferior parts of the brain are situated the 
nerve-centres, which originate and adjust the impulses 
necessary to complex body-movements, as running, bal- 

369. If the cerebral lobes are removed, what is the effect ? If the 
pons, peduncles, and ganglia? If the medulla? 

370. What impulses arise in the inferior parts of the brain? What 
external controlling influences ? What internal ? What of cerebral 
influences ? 



THE NERVOUS SYSTEM. 211 

ancing, writing, breathing, digestive movements, etc. The 
outer movements are carried out by motor nervous im- 
pulses arising in these nerve-centres, yet these centres are 
influenced, arranged, and controlled by impulses received 
from the outside through the senses of touch, sight, hear- 
ing, etc. In digestion, respiration, etc., the action of these 
centres is influenced by the impulses coming from the di- 
gestive tube, the lungs, etc. In bodily movements executed 
under the will, the cerebral hemispheres simply put this 
machinery in action. 

371. The peduncles of the cerebrum serve as the chief means of 
communication between the spinal cord and the superior parts of 
the brain. The peduncles and the pons are intimately connected 
with the co-ordination of movements. Complex bodily movements 
can be executed in the absence of the optic thalami, the corpora 
striata, and the cerebral hemispheres, but not in the absence of 
other parts of the brain. Injury to one side of the pons commonly 
causes paralysis of the muscles of the same side of the face and of 
the muscles of the limbs of the opposite side of the body. Hence 
the crossing over of impulses, beginning in the spinal cord (376), is 
gradually completed as the impulses pass through the pons. 

372. The cerebellum is an important organ of co-ordination (393). 
It receives motor and sensory impulses, and combines, influences, 
and adjusts them to produce correct movements. When this organ 
is severely injured, disorderly movements result; when it is re- 
moved, an almost total loss of control over body-movements super- 
venes. It is quite probable that its fiinctions are especially connected 
with the equilibrium impulses proceeding to the higher centres from 
the semicircular canals (475). 

373. The medulla oblongata is the link between the middle and 
lower spinal cord and the brain. The motor impulses from the 
cerebrum cross to the opposite side in the medulla. The majority 
of the "centres" for various reflex, protective, and organic functions 
are seated in this portion of the cord. The principal centres are 
the "respiratory" (184), the " vaso-motor" (135), the "heart inhib- 
itory" (128), tiie "artificial glycogenic" (308), the " doglutitiou" 
(2G1), the "gastric" and the "vomiting" (2C)(3), etc. 



212 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

374. Functions of the Spinal Cord. — If the cord of 
a dog be severed in the region of the back, the hind limbs 
remain flaccid and motionless. Stimulation of the hind 
foot evokes no symptoms of pain and calls forth no motions. 
The dog, if frightened, is unable to cause motions in his 
hind quarters. Stimulation of the lower cord at the point 
of section calls forth irregular movements in the hind 
limbs; stimulation of the upper cord at the same point 
gives rise to symptoms of pain, movements of the muscles 
near the section, and regulated movements above. If the 
animal recovers from his wound, the cord-sections not be- 
coming united, and if the hind feet be stimulated, a series 
of regulated, definite movements will be produced, — that 
is, reflex action. These reflex movements are often power- 
ful, varied, and complex (82). 

375. The Human Spinal Cord is the nerve-link con- 
necting the spinal nerves with the parts within the skull. 
It is a mere instrument for executing cerebral commands. 
It transmits outgoing and incoming impulses. The con- 
ductor is not simple, but is carried out by a system of 
relays (377). The path of least resistance is that of the 
white fibres, and it is inferred that motor impulses ordi- 
narily, and the sensory for most of the way, pass over the 
white tracts of their own side. The cord is the great seat 
of the centres for reflex action. The reflex centres of 
the cord control the sphincters of the bladder and rectum, 
exert a protective influence over the body, and execute 



374. What effect results from cutting the spinal cord ? What is 
the influence of later stimulation ? What are reflex action move- 
ments ? 

375. What is the spinal cord? What can it do? What is the 
path of least resistance ? What use does the brain make of the cord ? 
What do the reflex centres control ? 



THE NERVOUS SYSTEM. 213 

involuntary movements of the limbs, as the sudden with- 
drawal of a burnt finger, even in opposition to the will, 
or the withdrawing of the tickled foot during sleep or 
during deep mental action. The cord does not appear to 
possess automatic centres (84). 

876. As to the course pursued by different impulses, — of volition, 
of touch, of general sensation, of pain, — there is much indefinite- 
ness. The statements of the results arrived at by different experi- 
menters are conflicting and unsatisfactory. According to Schiff and 
his followers, the purely volitional impulses (motor) pass along the 
antero-lateral columns, and the purely tactile along the posterior 
columns of the same side, while the gray matter can transmit in all 
directions impulses of sensation and such outgoing impulses as are 
parts of reflex action. According to Brown-Sequard and others, the 
sensory impulses pass from the nerves along a certain length of the 
posterior columns, then cross over to the gray matter of the opposite 
side, in which they ascend to the brain ; the volitional impulses, 
having crossed in the pons (371) and medulla (373), descend in the 
antero-lateral columns, keeping to the same side. 

377. Experiments show that the gray matter of the cord is physio- 
logically continuous ; that it is marked out by physiological barriers 
of resistance into nervous mechanisms ; that these mechanisms carry 
out co-ordinated muscular movements and associate incoming im- 
pulses with these movements, — that is, reflex action. It is in- 
ferred that a volitional impulse for the production of a given body- 
movement, as of making a step, descending from the brain by the 
white tracts, passes into the gray matter of the cord at the place 
where the physiological mechanism for the execution of the given 
movement is located, and then emerges in the proper nerve ; and 
that the incoming impulse, as from^ the foot, passes at first into the 
mechanism with which that part is associated in producing a fre- 
quently-recurring reflex action, and that the impulse then travels 
up to the brain by a more direct tract than the gray mass. 

378. The brain uses the mechanism of the cord to do the coai-^e 
work of most body-movements, employing inferior brain-contres 
to supervise and control the action of the cord-mechanism. The 
more drilled and disciplined the cord-centres, the loss the ovoi-sight 
demanded of conscious brain-action. An unlrainod cord, as in a 



214 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



child, acts hesitatingly. An idiotic spinal cord only learns and 
executes under constant supervision, and quickly forgets its lessons. 
A healthy cord learns readily, remembers correctly, and executes 
the movements so well that in time little brain-supervision is 
demanded. 

379. A Sensory Nerve is a thread of communication between 
the sensitive cells of the external end-organ and the eminently 
automatic (84) or central cell. If a small object be applied to an 
appropriate end-organ, like the tip of the finger, the cerebral cen- 

FiG. 85. 




Fig. 85. A Vertical Section of the Cerebrum, Cerebellum, and Medulla Ob- 
longata, showing the relation of the cranial nerves at their origin.— 1, The cerebrum, 
2, The cerebellum, with its arbor vitr« represented. 3, The medulla oblongata. 4, The 
spinal cord. 5, The corpus callosum. 6,-The first pair of nerves. 7, The second pair. 
8, The eye. 9, The third pair of nerves. 10, The fourth pair. 11, The fifth pair. 12, 
The sixth pair. 13, The seventh pair. 14, The eighth pair. 15, The ninth pair. 16, 
The tenth pair. 19, The eleventh pair. 18, The twelfth pair. 20, Spinal nerves. 21, 
The tentorium. 



tres recognize the sensations to which an educated mind applies the 
terms " pressure/' " form," " hardness," etc. If the connecting nerve 
now be cut, and the same body be applied to the cut nerve-trunks, 
a sensation of pain only is recognized at the cerebral centres. 



THE NERVOUS SYSTEM. 215 

380. By a Motor Nerve is to be understood the thread 
of communication between the automatic or nerve cell of 
the centre and its muscular end-process (85). When a 
stimulus is applied to the centre of the given nerve, the 
transmitted impulse gives rise to a muscular contraction 
(87). The velocity of a motor impulse in the arm of man 
is about thirty-three metres (one hundred and eight and 
one-fourth feet) per second. The velocity of sensory im- 
pulses in man has not yet been well determined. In most 
cases the velocity of the impulses is retarded by cold and 
accelerated by heat. As yet, experiments have not shown 
that a purely motor trunk may act as a sensory trunk, and 
vice versa. 

381. The Cranial Nerves pass from the central ner- 
vous system (the pons and medulla, principally) outward 
by openings in the skull. They are arranged in twelve 
pairs, and distributed to the organs of special sense (Chapter 
XII.), to certain muscles of the face and neck, to the 
larynx, pharynx, heart, lungs, stomach, and intestines. 

382. Functions of the Cranial Nerves. — In these nerves the 
motor and sensory tracts are far less mixed than in the spinal nerves. 
The nerves of the senses of smell (first), sight (second), and hearing 
(eighth), are purely sensory. The third, fourth, sixth, and eleventh 
are purely motor. The others are mixed to a greater or less degree. 
Of the mixed cranial nerves, the fifth, seventh, and tenth are most 
important (Figs. 84, 85). 

The fifth, or trifacial, contains the motor fibres to the muscles of 
mastication ; the vaso-motor fibres of the head and face ; the secre- 
tory fibres to the tear-glands ; the dilator fibres of the pupils. It 
is the general nerve of sensation to the head and face and most of 
the mucous membrane of the mouth. Its first branch is distributed 



380. What is a motor nerve ? What is the velocity of a motor 
impulse? Of a sensory influence? 

381. Speak of the cranial nerves. What is a cranial nerve? How 
many ? To what distributed ? 



216 AXATOMY, PHYSIOLOGY, AND HYGIENE. 




about the orbit, the second about tbe superior maxilla, and the third 
to the inferior maxilla. It is the nerve of the special sense of taste 
(426) to the front part of the tongue. It is the nerve concerned in 
toothache and facial neuralgia. 

383. The seventh, ox facial., is the nerve of facial expression, being 
distributed to the muscles of the face. It emerges from the skull 

beneath the external 
^^^' ^^* ear. In paralysis of 

this nerve, the facial 
parts are drawn to the 
sound side, the eye is 
not fully closed, and 
the troubled side loses 
expression. The tenth^ 
p7ieumogastric or va- 
gus, is the motor nerve 
for the muscles of the 
pharynx, of the oesoph- 
agus, of the stomach, 
of the intestines, and 
of the larynx ; it is the 
A-aso-motor nerve of 
the lungs, and the inhibitory nerve of the heart. It is the sensory 
nerve of the air-passages, the pharynx, the oesophagus, and the 
stomach. It influences the respiratory and vaso-motor centres of 
the medulla, also the secretion of saliva and the pancreatic fluid. 
The cranial nerves play a very important role in the mechanism of 
human life. When healthy, they perform important duties with 
precision ; when diseased, they make life far from pleasant. 

384. The Spinal Nerves are arranged in thirty-one 
pairs. Each nerve arises by two roots, — the anterior , or 
motor-impulse-transmitting root, and the posterior^ or sen- 
sory-impulse-transmitting root. The latter has an em- 
bedded ganglion, behind which the two roots unite into 
one nerve. The nerve, thus formed, passes from the spinal 

384. How many spinal nerves? How many roots? How do nerves 
leave the canal ? To what distributed? Their function? 



Fig. 86. Teansverse Section of Spinal Cord.— 1, 2, 
Spinal nerves of right and left sides, showing their two 
roots. 4, Origin of anterior root. 3, Origin of posterior 
root. 5, Ganglion of posterior root. 



THE NERVOUS SYSTEM. 



217 



Fig. 87. 



canal by an intervertebral opening. The spinal nerves are 
distributed to the viscera, muscles, and skin below their point 
of exit. They transmit both sensory and motor influences. 

385. All spinal nerves are composed of motor and sensory fibres. 
When a spinal nerve is divided, the stimulation, as by heat, scratch- 
ing, electricity, etc., of the trunk-end 
causes a sensation in the conscious cen- 
tres, or a reflex action in another mus- 
cular area; stimulation of the distal 
end causes muscular contractions in its 
own area. When the anterior root 
only is cut, the muscles supplied by 
that nerve cease to be caused to con- 
tract either by the will or by reflex 
action, while the structures to which 
the nerve is distributed retain their 
sensibility. If the trunk-end is stimu- 
lated, no sensory eflect is produced ; if 
the distal end, the muscles are caused 
to contract. When the posteiior root 
is cut, the muscles to which the nerve 
is distributed may be caused to con- 
tract by the exercise of the will or 
through reflex action ; but the parts to 
which it is distributed lose their sensi- 
bility. If the trunk-end is stimulated, 
sensory effects are produced; if the 
distal end, no sensory effects or move- 
ments occur. The ganglion on the pos- 
terior root appears to be concerned 
only in the nutrition of the nerve. 




Fig. 87 (Leidy). Segment of the 
Spinal Cord. — 1, Anterior median 
fissure. 2, Posterior median fissure. 
3, Postero-lateral fissui'e. 4, Antero- 
lateral fissure. 5, Anterior column. 
6, Lateral column. 7, Posterior col- 
umn. 8, Anterior commissure. 9, 
Anterior horns of the gray sub- 
stance. 10, Posterior horns. 11, 
Gray commissure. 12, Anterior root 
of a spinal nerve springing by a 
number of filaments from the an- 
tero-lateral fissure. 13, Posterior 
root from postero-lateral fissure. 

14, Ganglion on the posterior root. 

15, Spinal nerve formed by the 
union of the two roots. 



If the nerve-ganglion be excised, the whole posterior root dcgeneratos, as well as the 
sensory fibres of the mi.xed nerve. When the posterior root is cut between the ganglion 
and the cord, the cord-portion degenerates. If the anterior root bo cut, the motor nerves 
in the distal portion degenerate. The knowledge of these fiicts led Waller to employ ex- 
cision and cutting to determine accurately the distribution of sensory and jnoti>r fibres. 
In 1811, Charles liell distinguished between the motor and sensory fibres. In ISJ'2. IMiv- 
gendie showed the functions of the anterior and posterior roots. These discoveries laid 
the foundation of modern nerve i)hysiology. In 1S;>2, Marshall Hall's experiments estub- 
liehed the theory of rellex action. 

K 19 



218 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

386. The Sympathetic System (344) consists of two 
chains of ganglia (gray nerve-masses), one on each side of 
the vertebral column. This double chain extends through 
the deep parts of the neck into the chest and abdomen. 
The ganglia communicate with one another, with the spinal 
cord, with the ganglia seated in or on the viscera of the 
thorax and abdomen, and with certain of the cranial nerves. 
The nerve-fibres of this system are distributed to the mus- 
cular fibres of the blood-vessels (vaso-motor). 

387. Functions. — The sympathetic system presides over 
the viscera of the body. It has been named the ^'nutritive 
nervous system." It exerts its influence over the viscera 
and the body at large by the control it exercises over the 
calibre of the blood-vessels. Its ultimate branches are 
called the vaso-motor nerves (134), and through them the 
vaso-motor centre (373) makes its influence felt. This 
system is assisted by, and is subordinate to, the cerebro- 
spinal system. 

388. Summary. — The functions of motion, of sensation, 

Fig. 88. A Back View of the Brain and Spinal Cord.— 1, The cerebrum. 2, The 
cerebellum. 3, The spinal cord. 4, Nerves of the face. 5, The brachial plexus of nerves. 
6, 7, 8, 9, Nerves of the arm. 10, Nerves that pass under the ribs. 11, The lumbar plexus 
of nerves. 12, The sacral plexus of nerves. 13, 14, 15, 16, Nerves of the lower limbs. 

Fig. 89 represents the Sympathetic Ganglia, and their Connection with other 
Nerves. — A, A, A, The semilunar ganglion and solar plexus, situated below the diaphragm 
and behind the stomach. This ganglion is situated in the region (pit of the stomach) 
where a blow gives severe suffering. D, D, D, The thoracic (chest) ganglia, ten or eleven 
in number. E, E, The external and internal branches of the thoracic ganglia. G, H, The 
right and left coronary plexus, situated upon the heart. I, N, Q, The inferior, middle, 
and superior cervical (neck) ganglia. 1, The renal plexus of nerves that surrounds the 
kidneys. 2, The lumbar (loin) ganglion. 3, Their internal branches. 4, Their external 
branches. 5, The aortic plexus of nerves that lies upon the aorta. The other letters and 
figures represent nerves that connect important organs and nerves with the sympathetic 
ganglia. 

386. Of what does the sympathetic system consist ? Where found ? 
"What connections ? How distributed ? 

387. What are its functions? What control does it exercise? 
What portion influences its action ? 



THE NERVOUS SYSTEM. 



219 




Fig. 89. 




220 

of the regulation of actions, of the special senses, as well 
as of digestion, absorption, nutrition, circulation, respira- 
tion, secretion, and excretion, are placed more or less under 
the control of the nervous system. This 'system of nerve- 
centres and of impulse-conducting fibres plays the part 
of an excitor and regulator in regard to the functions of 
the other tissues. The paths and the centres of all the 
functions of the body are structurally associated. The 
anatomical links, the nerves, are exceedingly numerous, 
and intricate in distribution. The physiological relations 
between all parts, even the most distant, are most intimate, 
and are also interdependent. 

389. As a result of the close anatomical connection and 
physiological relation, all parts of the body are more or 
less in sympathy with one another. The odor from the 
engine-room of a steamer excites nausea ; the thought of 
a savory dish causes a flow" of saliva ; the sight of an 
animal in pain induces a painful sensation in the mind ; a 
sudden mental emotion accelerates or retards the beat of the 
heart ; disease in one eye often leads to a similar malady 
in the other ; a severe burn induces ulceration of the 
duodenum, etc. During life, under the excitation and 
regulation of the nerve-centres, an active co-ordination of 
all the parts of the body is sustained, and the organism is 
enabled to execute the duties for which it w'as designed, — 
growth, work, and the continuance of the species. 

390. Summary {Continued). — 

Cerebrum. — Psychical faculties: perception, ideation, 
reasoning, emotion, volition, and the faculty of language. 

388. "What functions are under nervous control? "What part does 
it play ? What of the anatomical links ? Physiological relations ? 

389. What are the duties of the organism ? 

390. "Write on the slate a summary. 



THE NERVOUS SYSTEM. 221 

Olfactory lobes. — Sense of smell. 

Optic thalami, ")" Middle-men '^ between the peduncles 

Corpora striata./ and the cerebral centres. 

Corpora quadrigemina. — Centre for sight, centre for 
co-ordination of eyeballs and pupil. 

Peduncles^ | Parts of communication concerned in co- 

Pons. J ordination. 

Cerebellum. — Important organ of co-ordination. 

Medulla. — Seat of centres for various organic functions. 

Spinal cord. — Conductor of impulses, centre of certain 
reflex movements. 

Ganglia. — Centres of automatic nerve-action. 

Nerves. — Conductors of impulses. 

End-organs. — Receivers of impressions. 

391. Spasms, or Convulsions, are involuntary contractions of the 
skeletal muscles, varying widely as regards their intensity. When 
accompanied by severe pain, they are known as cramp. They are 
caused by irritations acting on some portion of the nervous system, 
causing the explosive discharges in the nerve-centres known as 
impulses (349). In children, gum-irritation (in teething) and di- 
gestive irritation are the most common causes ; in adults, the pres- 
ence of irritants in the blood, in the alimentary tube, or in the 
fleshy parts. Tetanus, or " lock-jaw," is commonly started by some 
irritant, as a splinter in the flesh, or a drug, like strychnia. Paral- 
ysis, or palsy, is the suppression of the transit of motor impulses to 
a certain extent. It may be general, involving most of the body, 
or local, as in wrist-drop. It results from degeneration or disease 
in the central cells, from pressure upon or injury to the central 
cells, or from section or pressure of the nerves in their coui*se. 

392. Hemiplegia is one-sided paralysis. In most cases, the nuis- 
cles of the arm, the leg, the trunk, and the lower part of the face in- 

•dicate the suspension of motor-impulse conduction. In the majority 
of cases the seat of mischief is within the skull. The most com- 
mon factor is the escape of blood into the cerebral tissues. The 
escaping blood rends apart the tissues, or its accunuilation presses 
upon the soft structures, thus stopping- coU-aotiou. The absorption 

19*^ 



222 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

of tlie clot is frequently followed by a partial recovery of the motor 
functions. Paraplegia is a paralysis of both sides of the lower 
part of the body. It commonly results from injury or disease of 
the spinal cord. The lesion of the cord frequently follows injury 
to or malformation of the vertebral column. It may occur at any 
part of the cord. The nearer the medulla the seat of the trouble, 
the greater the inconvenience, as well as the danger to life. Paral- 
ysis may be local, as in facial paralysis, due to sudden chilling of 
the face, or to the cutting of the nerve. All forms of sensation 
may be more or less impaired, lost, exalted, or perverted, as in 
anoBsthesia, hypercesthesia, neuralgia, etc. 

393. Co-ordination is the adjustment of the outgoing impulses 
from a nerve-centre to the incoming impulses. The adjustment 
of the nervous impulses to the duties at hand obliges the muscles 
to contract in proper order, at the proper time, and to the proper 
extent, thus occasioning orderly, purposeful movements (515). The 
interval between the arrival at the central cells of the incoming 
impulses and the departure from them of the outgoing impulses is 
a busy time for the protoj^lasm of the nerve-cells of the centre. 
During this interval many processes, chemical and physiological, 
of which at 2)resent we know little or nothing, are being carried 
out. 

394. Habit. — This is the disposition which the organism acquires 
from the frequent execution of certain acts to repeat these acts 
until some more powerful forces intervene. The influence of habit 
over the ordinary operations of the central system is well known. 
Owing to having stated hours for eating and drinking, the sensa- 
tions of hunger and thirst are rarely experienced at other periods 
of the day. The user of tobacco and alcoholics, the votary of 
opium, or chloral, or hashish, is subject to the same influence. 
The user invariably feels the urgent need of the customary stimu- 
lant or sedative- when its ingestion is even slightly delayed. In 
some persons, the interruption of an accustomed habit so affects 
their mental actions that they will undergo inconveniences and 
will run physical and social risks rather than not indulge the 
habit (dipsomania). A habit once firmly fixed cannot be turned 
aside without causing deep inconvenience to the entire system. 

395. In explanation of the phenomena of habit, physiology can 
offer nothing definite. In the physical world, a force once acquired 



THE NERVOUS SYSTEM. 223 

will continue indefinitely if no more powerful force, or combina- 
tion of forces, interfere with it. In the nervous system it may be, 
as a series of impulses acting on the centres call forth certain ac- 
tions, that the impression of the impulse at the centre is not effaced 
with the accomplishment of the resulting act ; that the arrival of 
the given series of impulses at the given centres at regular intervals 
deepens the impression; that the influence of these impressions 
becomes so deeply worked into the activity of the centres that the 
centres, after a time, become able to produce the associated actions 
without the arrival of impulses from without, and that thus a habit 
becomes fixed and influential. 



HYGIENE. 

396. For the proper performance of their functions the 
different organs of the body are dependent upon the im- 
pulses originating in the nerve-centres. Upon the integ- 
rity and proper working of all parts of the nervous system 
depends the healthy action of each part and of the whole. 
Owing to the intimate relations of the great nerve-centres 
to all organs, improper action or imperfect performance of 
duties by the organs is quickly and markedly manifested 
by irregular, spasmodic, abnormal, and even painful action 
of the superior centres. The physical condition of the 
system affects reflex action, co-ordinate action, sense action, 
and mental action. The hi2:hest health and viiror of the 
nervous system require — (1.) A sound nervous organization 
by inheritance. (2.) A sufficient supply of normal blood. 
(3.) The judichms and regular exercise of the body and the 
brain. (4.) The ability to secure normal sleep and rest. 



390. What influonco do ncrvo-iinpulsos i>\cM-t? What rosults; tVom 
intimnto relations and close connections? AVhat are atleoted by the 
pliysieal condition of the system ? Wiiat is reiiuired for tlie hiu;liest 
liealtli of tlu> lUM-vous system? 



224 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

397. I. — A Sound Nervous Organization by In- 
heritance. — Every-day observation shows that children 
inherit not only the features, but the physical, mental, and 
moral constitution of their parents. Even those utterly 
ignorant of the laws of transmission are wont to estimate 
the child according to its family : favorably, if of a '^ good 
family" or '^ good blood ;" unfavorably, if of a " bad family" 
or ^^ bad blood." Every formation of body, internal and 
external, all intellectual endowments and aptitudes, and all 
moral qualities, are or may be transmissible from parent 
to child. If one generation is missed, the qualities may 
appear in the next generation {atavism), A guilty secret 
may thus reveal itself long after the active participators in 
it have passed from this life. 

398: It is important to notice that not only the natural constitu- 
tion of the parents may be inherited, but their acquired habits of 
life, whether virtuous or vicious ; and especially is this true of the 
vicious. Even when the identical vice does not appear, there is a 
morbid organization and a tendency to some vice akin to it. Not 
only is the evil tendency transmitted, but what was the simple prac- 
tice, the voluntarily adojDted and cherished vice, of the parent, be- 
comes the passion, the overpowering impulse, of the child. A 
person thus is often handicapped for life by the mistakes and faults 
of his ancestors. 

399. M. Morel sketches the history of four generations as fol- 
lows: ''First Generation. — The father was an habitual drunkard, 
and was killed in a public-house brawl. Second Generation. — The 
son inherited his father's habit, which gave rise to an attack of 
mania, terminating in paralysis and death. Third Generation. — 
The grandson was strictly sober, but was full of hypochondriacal and 
imaginary fears of persecutions, etc., and had homicidal tendencies. 
Fourth Generation. — The fourth in descent had very limited intelli- 



397. "What expression of a great truth ? How do we estimate per- 
sons ? What is transmitted ? What is atavism ? 



THE NERVOUS SYSTEM. 225 

gence, and had an attack of madness when sixteen years old, ter- 
minating in stupidity nearly amounting to idiocy ; with him the 
race probably became extinct." 

400. " Habits of growing drunkenness in parents have the effect 
of inclining the children to grow up instinctive drunkards, and the 
first children born, ere the habits are confirmed, are free from the 
vice which holds the younger children fast in a disgraceful thral- 
dom." — Fothergill. " Of three hundred idiots in Massachusetts, Dr. 
Howe referred one hundred and forty-five directly to intemperance. 
A like proportion of insanity finds a similar reference. If we add 
to these all the degrees of weakness, imbecility, and deterioration 
which lie between these extremes of idiocy and insanity on the one 
hand and sound manhood and sound-mindedness on the other, what 
a dreadful and unending entail have we as the product of this one 
vice [of the parents] !" — Bascom (245, 408). 

401. Says a famed physician, after long and close observation of 
the evil effects of tobacco, " If the evil ended with the individual 
who, by the indulgence of a pernicious custom, injures his own 
health and impairs his faculties of mind and body, he might be left 
to his enjoyment, his fool's paradise, unmolested. This, however, is 
not the case. In no instance is the sin of the father more strikingly 
visited upon the children than in the sin of tobacco-smoking. The 
enervation, the hysteria, the insanity, the dwarfish deformities, the 
consumption, the suffering lives and early deaths, of the children 
of inveterate smokers bear ample testimony to the feebleness and 
unsoundness of the constitution transmitted by this pernicious 
habit" (412). 

402. Should we trace the effects of the whole list of vices, it would 
be with equally sad results. Even of the great love of money-getting, 
a celebrated physician writes, " I cannot but think, after what I 
have seen, that the extreme passion for getting rich, absorbing the 
whole energies of a life, does predispose to mental degeneration in 
the offspring, either to moral defect, or to moral and intellectual 
deficiency, or to outbreaks of insanity." — MamUlcy. 

403. Any kind of nervous disease in the parents, whether natural 
or acquired, seems to })redispose to innate feeblenoss in the child. 
The offspring of " fast" parents are too often weakly and delicate. 
The disease received by inheritance may ai)})ear at birth, it may not 
appear until a definite period after birth, or it may lie dormant until 

P 



226 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

brought out by an extraneous exciting cause. The hereditary ten- 
dency to diseases is intensified by the intermarriage of those suffer- 
ing from the same affection, as of phthisis, insanity, neuralgia, etc. ; 
by the marriage of those closely related ; by the marriage of the 
very young ; or by the marriage of those of very unequal ages. It 
therefore behooves every one to see that his family shall not suffer 
from the sins and follies of his generation. By judicious education, 
and a strict obedience to physical and mental regimen, a naturally 
defective constitution may be improved. 

404. II. — A Sufficient Supply of Normal Blood. 
— The nerve-centres are not only delicate in structure and 
easily influenced, but are very vascular. The circulation 
of the blood in the centres is rapid and very essential. 
The tissue-changes in the protoplasm of the blood are 
rapid. The brain, though weighing less than one-fortieth 
of the body, is said to receive one-fifth of the blood ex- 
pelled by the left ventricle. Hence it is that impurities 
in the blood so rapidly affect the superior nerve-centres. 
Therefore it is of the highest importance, for the proper 
working of the nervous system, that the blood be sufficient 
in amount, contain all the nutrient elements (214, 114), 
be properly oxygenated (181), be relieved of all products 
of tissue- waste at the earliest possible moment (316), and 
that impurities and foreign materials (alcohol, chloral, mor- 
phia, etc.) be rapidly eliminated. Whatever deteriorates 
the quality of the blood impairs the health of the nervous 
system. 

405. The effects of ^joor ventilation are soon manifest in 
the nerve-centres, — drowsiness, dulness, headaches, nausea, 
etc. An improper foody or a good food improperly pre- 

404. Why is a supply of normal blood needed ? What of the brain 
blood-supply ? What is therefore essential ? 

405. What results from imperfect ventilation ? From a poor or 
bad diet ? From bad bread ? 



THE NERVOUS SYSTEM. 227 

pared, Is not well assimilated, and the blood, in turn, is not 
put in condition to afford proper tissue-food. The effects 
of a bad diet are most marked in brain-workers, as distin- 
guished from hand-workers. No teacher can teach well, 
no lawyer can plead well, no clergyman can preach well, 
who habitually takes improper food. Poor bread in the 
United States is said to cause more physical mischief than 
alcohol. An improper diet not only induces dyspepsia 
(281), but influences the brain -centres, causing confused, 
morbid emotions and weakened will-power. 

406. For the integrity of the working of the nerve-centres, 
it is important that the excretory apparatus of the skin, of 
the lungs, of the bowels, and of the kidneys be in good 
working order. The retention in the blood of the prod- 
ucts of normal tissue- waste induces headache, confusion of 
ideas, dimness of vision, nausea, and, in some cases, de- 
lirium, stupor, and death (305). The circulation in the 
blood and the slow elimination of the active principles of 
certain drugs and foods have a most injurious influence upon 
the action of the nerve-centres during the presence of the 
poisons in the blood, and even after their passage from the 
blood by way of the urine, the breath, and the perspiration. 

407. Stimulants and Sedatives. — At present a num- 
ber of drugs useful in the alleviation of pain, in the 
meeting of certain surgical and medical emergencies, and 
in the prolonging of life, are extensively used by the people 
for their stimulating or their quieting effects on the cen- 
tral nervous system. At first a small quantity produces 

40G. What result from iniporfoet oxcrotion ? From tlio pro.^oiioo of 
poisons ? 

407. W^hftt do tho people laro-oly use ? AVlint is Oio etioct of a small 
quantity? Of continued use ? Of a larger quantity ? AVhat is said 
of the craving? 



228 ANATOMY, PHYSIOLOGY, A>;D HYGIEXE. 

the characteristic and desired effect; later, the system 
having become accustomed to the presence of the foreign 
agent in the blood, a larger dose must be employed to get 
the desired stimulation or sedation (394). These drugs, in 
definite, small doses, are fatal poisons ; but the system be- 
comes so habituated to them as to endure with immunity 
doses which if taken at first would produce rapid death. 
Under their voluntary, continued use, the system is edu- 
cated into a craving for them. This craving becomes so 
strong that the will-power of the consumer is unable to 
resist the demand for the degrading, baneful drug, though 
the injurious effects are felt and acknowledged. 

408. Alcohol (241) taken into the system effects rapid 
changes in the working of the nerve-centres. When taken 
continuously, it impairs the nutrition of these centres. 
Each successive indulgence increases the abnormal nutri- 
tion and strengthens the demand for alcoholics. Im- 
paired cell-nutrition induces imperfect, abnormal, or per- 
verted action, — mental, organic, muscular. As a result 
of the deterioration of nutrition in the superior brain- 
centres, the power to resist the craving for intoxicants 
grows feebler and feebler, and at the same time the intel- 
lectual and physical powers are diminished. The effect on 
the nervous system of the abuse of the intoxicating prin- 
ciple of all spirituous liquors ranges from drunkenness 
and acute poisoning, through alcoholic mania, acute and 
chronic alcoholism, to dipsomania. The diseased condi- 
tion caused by intoxicating drinks in the parents tends 
to induce nervous enfeeblements in the offspring, as epi- 
lepsy, insanity, imbecility, neuralgia, etc. (400). Bruehl- 



408. Effect of alcohol upon the nerve-centres ? Of impaired cell- 
nutrition? "What is the rano;e ? 



THE NERVOUS SYSTEM. 229 

Kramar maintains that the inebriety of the father has a 
more baleful effect on the offspring than the intemperance 
of the mother (67a, 87a, 147a, 209a, 243, 270, 290, 305a, 
338a, 394, 516). 

In drunkenness, the early mental and physical exhilaration, the irregular action of 
mind and body, the loss of control over the head and limbs, the deep, narcotic sleep, as 
well as the succeeding muscular and mental depression, the nausea and perverted sensa- 
tions following the debauch, are, painfully, too well known. In acute poisoning, the in- 
fluence may be so powerful as to cause dangerous sleep, loss of sensation, coldness of the 
surface of the body, feeble pulse, and speedy death. In mania, there is a fixed delusion 
at times, especially in those who have Inherited a love for ardent spirits. Acute alco- 
holism (" the horrors") is characterized by tremor, restlessness, wakefulness, and a dis- 
turbed, anxious expression of the features. In this state, there is a want of appetite, 
frequent and feeble pulse, a marked depression of spirits, an inability to concentrate the 
mind on any subject ; the affected person becomes vacillating, suspicious, quarrelsome, 
and cowardly. He has frightful dreams, hallucinations of hearing, seeing, smell, and 
taste. In chronic alcoholism as the result of the steady use of intoxicants for a consider- 
able period, there is a striking deterioration of physical health, together with mental 
and bodily debasement. The memory and judgment are weakened, the different facul- 
ties of the mind are in abeyance. The person becomes untruthful, cunning, or cowardly^ 
indiff'erent to the wants of those dependent on his exertions ; often suffers from deep 
mental depression, with suicidal tendencies ; the end is frequently general paralysis or 
dementia. In dipsomania, there is an uncontrollable impulse, " thirst" for alcoholics. It 
is a form of insanity. From a physiological point of view, it is hard to reform "chronic 
inebriates." Their nerve-centres have become so perverted in their action that they 
have lost self-control ; 'the inherited coupled with the cultivated appetite demands a 
resistance beyond their powers. 

409. Chloral is a hypnotic. It is a recent and a most seduc- 
tive drug. Tlie people have rapidly learned that it produces sleep 
and relieves restlessness and " nervousness." It is resorted to in 
order to produce sleep, as alcohol is to drown shame, and opium to 
deaden pain, and thus the "chloral habit" often becomes as per- 
nicious as the "opium habit." Persons commencing with small 
doses become habituated to it, and are compelled to use larger and 
larger doses, until they are enslaved to the drug-craving. 

In chronic chloraUsm there is marked muscular weakness, espe- 
cially of the legs ; there is feeble action of the heart, cold extremi- 
ties, a tendency to profuse sweating, and peculiar cutaneous symp- 
toms. Under its use the consumer becomes dull and dreaniy, the 
will-power vanishes, the judgment is impaired, and the intellectual 
faculties are blunted. It is a dangerous drug. From it there are a 
large number of recorded cases of ])oisoning and death. It is often 
cumulative in its action. It should be used only under the direc- 

20 



230 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

tion of an educated medical man, and continued only while under 
his care. 

410. Hashish, or Indian Hemp, when given in full doses, pro- 
duces a feeling of exhilaration, with a condition of revery. In 
the East it has long been employed as an exhilarating intoxicant, — 
a producer of deep sleep with an unconsciousness to pain. It in- 
duces a sense of prolongation of time, — that is, ideas are evolved 
with extraordinary rapidity. Its use may lead to catalepsy and to 
convulsions. It is not as pernicious in its effects as opium, yet its 
habitual use is not devoid of danger to the nervous system. It is 
an ingredient in several nostrums for the production of euthanasia 
in the advanced stages of phthisis. 

411. Opium and its derivative morphia are most useful and most 
dangerous. The number of habitual consumers of morphia and 
opium appears to be on the increase in the United States, as well 
as in China and the East. In therapeutic doses, opium induces a 
quieting effect, accompanied by a peculiar dreamy condition. It is 
commonly stated that after taking opium there is a stage of in- 
creased mental activity. This is seen most frequently in those who 
take it habitually as a stimulant. The habitual opium-taker be- 
comes spare of body, his appetite diminishes, his skin grows sallow 
and parchment-like, and the functions of portions of the glandu- 
lar system are in abeyance. There is a marked deterioration of the 
will-power and of the memory, a manifest inclination to deceive 
and lie about the habit, a noticeable lack of attention to proper 
business, and a decided change in the moral tone. Actual mania or 
dementia may result from the long-continued use of the drug. To 
produce the desired effect, the amount of the drug used has to be 
steadily increased. The inability to get the drug in suflBcient 
amounts and at the proper time causes mental and physical tor- 
ments. 

The hypodermic method of taking morphia is the most dangerous, both immediately 
and remotely. The opinm-smoking method is less injurious than any other form of the 
opium habit. In the opinion of Dr. H. Kane, opium-smoking works less harm to the 
individual and to the community than alcoholism. A dangerous combination of tobacco 
and opium in the form of cigars and smoking-tol)acco has recently come into use, by 
which the bad features of both drugs are made more seductive and more dangerous. 

412. Tobacco is a j)oison that modifies the energies, and 
not the structure, of the nervous system. It is an evasive 



THE NERVOUS SYSTEM. 231 

poison; no traces are stamped on the body, such as the 
" hob-nail liver" produced by alcohol. It, however, has a 
baneful effect on but a minority of adults who use it in 
moderation ; and when the use of the weed is abandoned 
by adults, the worst effects generally disappear rapidly. 
In smoking, carbonic acid, carbonic oxide, several ammo- 
nias, and crude nicotin are drawn into the air-passages. 
Portions of the two latter enter the blood-current, circu- 
late with the blood, work mischief in the nerve-centres, 
and are principally eliminated by the kidneys. The poison- 
ous effect on the system is induced by the ammonias and 
the nicotin. The marked evil effect in adults is upon the 
mucous membrane of the air-passages : the tonsils are en- 
larged, the throat becomes red and dry : in short, the 
"smoker's sore throat" is established. The reports of the 
effects of tobacco on the digestive and nutritive functions 
are conflicting (286). Tobacco alone rarely produces 
feebleness of vision, but tobacco and alcohol not unfre- 
quently cause " tobacco amblyopia." In general, more 
intellectual work can be done without tobacco than with it. 
On the youthful and the immature, the effects of tobacco, 
in what form soever taken, are pernicious. The processes 
of nutrition are diminished and the growth stunted; the 
innervation of the heart is disturbed ; its action becomes 
weak, irregular, and intermittent, causing palpitation, faint- 
ness, and dizziness; muscular co-ordination is impaired, for 
it is said that youthful smokers cannot draw a " clean 
straight line." Certain glands, at first, are stimulated, 
especially by cigarette-smoking, but later become markedly 

412. Why is tobacco culled an evasive poison? What results tVoni 
smoking? What are the active poisonous ag-ents? Describe the 
" smoker's sore throat." Wlnit is the elVect on the young? Why is 
tobacco a bane to youth ? What conclusion ? 



232 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

debilitated; the power of concentration of mind is lessened, 
the intellectual activity is said to be impaired, and the whole 
individual is crippled. Tobacco is a bane to the youth of 
the world. No boy from ten to fifteen years old can prac- 
tise smoking or chewing the weed without becoming men- 
tally and physically less efficient when he reaches his ma- 
jority than he otherwise would have been. Tobacco is not 
a food. Its consumption in the system does not evolve 
energy or heat, though it may enable a man accustomed 
to using it to continue work for a longer period when the 
accustomed food is protracted. For all young people, and 
for most adults, it would be healthier not to use tobacco in 
any form as an indulgence or a solace. 

413. III. — The Judicious and Regular Action of 
ALL Parts of the Organism. — Exercise (519) of the 
skeletal muscles is an indispensable condition for health of 
the brain and nervous system. Exercise compels the 
blood to flow more freely and fully, stimulates the ex- 
cretory organs, sharpens the appetite, induces the taking in 
of more food and promotes its absorption and assimilation, 
and thus the blood offered to the cells of the nerve-centres 
is made richer, clearer, and more invigorating. The effect 
of insufficient exercise is felt in the brain, through the 
resulting indigestion and the deficient excretion by the 
bowels, lungs, and kidneys, as mental dulness and heavi- 
ness, impaired memory, impairment of the power of con- 
centration, headache, neuralgic pains, etc. In persons who 
are merely sedentary, having little occasion for active 
thought, this want of exercise is sufficiently mischievous ; 
but where there is great mental activity the mischief is 

413. "What results from muscular exercise ? How does deficient 
exercise afiect the brain ? "What of business-men ? Of the English 
nobility ? Of mental conditions affecting bodily health ? 



THE NERVOUS SYSTEM. 233 

vastly increased. Hundreds of ministers, lawyers, and 
counting-room employes shorten their days because of this 
neglect. Especially is this the case in America. The 
English nobility, notwithstanding their many indulgences, 
are a long-lived race, and this is doubtless owing to their 
spending so much time in open-air exercise. That the 
bodily organs may be directly affected by impressions 
purely mental does not admit of doubt. Of this fact the 
skilful physician never loses sight ; for a hopeful, health- 
ful influence of the mind may be made a remedial agency 
quite as powerful as that of drugs, batteries, and baths. 

414. Mental Exercise. — Regular and systematic men- 
tal exercise is essential to the health of the brain-cells. The 
nerve-cells need careful, methodical, graduated exercise, in 
order to increase their activity and efficiency. As the 
gymnast becomes expert not by spasmodic efforts, but by 
accurate, persistent drill, so must the mental athlete gain 
his power by the regular performance of such exercise as 
he is able to bear. The gymnast at first feels pain in his 
muscles, but he has only to persevere, with proper intervals 
of rest, and what was at first difficult becomes easy, while 
power is gained for severer feats. A person unaccustomed 
to mental gymnastics feels headache and confusion at first, 
but frequent repetition makes easy and natural the hitherto 
laborious efforts. By exercise the nerve-cells will gain that 
firmness which increases their capability for action. 

415. The amount of mental exercise should be adapted to the 
health and age of the individual. If from any cause the ner- 
vous system be weakened, an amount of exercise which would be 
quite harmless to one in health may prove disastrous. The nerve- 



414. What is tlie effect of systomatic muscular work? (^f sys- 
tematic mental work? AVliat iniluonco on the brain-colls? 

20^^ 



234 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

tissue of children and youths needs care ; for overwork that in the 
adult is followed by fatigue, easily removed by rest, in the child 
may result in irreparable injury. Much evil undoubtedly arises 
from school-children remaining too long in cramped or otherwise 
restrained positions in ill-ventilated, poorly-lighted, improperly- 
desked school-rooms; but much more results from the excessive 
and premature strain to which the youthful brain is often subjected 
under the greater variety of instruction which is imparted under 
modern systems of education. Parents and teachers should not 
fail to remember that there are important differences in the quality 
of different brains. In some children the mental reaction to im- 
pressions is sluggish and incomplete ; in others, again, the reaction 
is rapid and lively, but evanescent, so that, though quick at per- 
ception, they retain ideas with difficulty ; while in others there is 
that just equilibrium between the internal and external in which 
the reaction is exactly adequate to impression. These differences 
should be taken into account. 

416. Education. — The researches of Dr. Chausier 
showed only one hundred and twenty-two out of twenty- 
three thousand two hundred newly-born infants to possess 
abnormal bodily peculiarities of any kind. Every child's 
mental future depends on that which it has inherited from 
its ancestors, upon the influences received from books at 
school and at home, and from the examples about it. If 
possible, the early book-knowledge should be inculcated at 
home. The minutes devoted to the study of one subject 
should be few, but the work should be earnest and the 
repetitions frequent. Dr. Chadwick is of the opinion that 
a child from the age of five to seven can attend to one 



415. How should mental work be proportioned ? What of the 
nerve-tissue of children ? What evils in the modern school system ? 
Speak of mental reactions. Effects of the forcing system. 

416. Upon what does a child's mental future depend? What of 
early mental work? What is Dr. Chadwick's opinion? What in- 
jurious influences in school-life? 



THE NERVOUS SYSTEM. 235 

subject fifteen minutes; from seven to ten years, about 
twenty minutes ; from ten to twelve, about twenty-five 
minutes ; and from twelve to sixteen, about thirty minutes. 
The day-school is preferable for children to the boarding- 
school, with its atmosphere of discipline and routine. One 
of the great causes of overstraining in youth is the oifering 
of prizes for the best exhibit in the faculty of memorizing. 
Of the causes of the physical deformities produced in 
school-life, bad air (sewer and once-breathed), poor lights, 
constrained positions, too long hours, and want of active, 
interesting exercise are most prominent. 

417. Let the drill of school- children and youth be confined to a few 
subjects. Restrict those subjects in the public- schools to the topics 
which are needed by the average citizen in ordinary life, — a knowl- 
edge of arithmetic, letter-Avriting, geography, history, human physi- 
ology and hygiene, plant-life, and animal life. Let the drill be vigor- 
ous, thorough, and progressive. Require the culture to be not of the 
memory alone, but of the powers of observation, of comparison, and 
of reasoning. Take the necessary time to accomplish a few things 
well. Let the study be intensive, not trivial and prolonged. Allow 
frequent intervals for rest, or for changes of position. Also instruct 
the young how to use properly the tools employed in daily adult 
life. By such a course the brain-centres will be in a state of sound 
health, and will be fitted for continuous enduring mental labor 
during youth, maturity, and age. But permit the brain-centres to 
be weakened in childhood and youth by diffusive studies, by pro- 
longed lounging and dawdling over books, by cultivation of memory 
of words, by the production of a brain-dyspepsia, and the brain 
must ever work weighted and held back by ill-trained and per- 
haps permanently diseased centres. 

418. Harmonious I)evelop]\[ent of Girls.— The effect of the 
modern educational forcing system on boys is faulty enough, but 
more censurable on girls. The overwork tliat is forced on the miss 
entering her teens, from dress and tlu^ customs of society, in con- 
nection with the varied studies and exercises mapped out in the 
graded and higlier scliools, exhausts the nervous energies, stunts a 
proper physicnl dovoIopnuMit. and leaves the brain clogged with 



236 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

unassimilated material, which soon vanishes from want of a slower 
and more sterling culture. The A^tal energies and nerve-force 
which are thus dissipated should be devoted dui-ing youth to the 
consolidation of the physical system and invigoration of the mind. 
To have a healthy, w^ell-balanced mind, the body must be strong 
and symmetrically developed. The culture of the feelings should 
be in harmony with the intellect. If either sex needs a high, har- 
monious development more than the other, physically, mentally, 
and morally, it is the woman. It is due to the home, due to the 
future of the country. 

419. Says Dj:. Eay, " I have no hesitation in sayicg that, of all 
the means for preserving health, there is nothing more sure, or 
better suited to a greater variety of persons, than habits of regular 
and systematic mental occupation of some dignity and worth. In this 
proposition I would embrace all those kinds of employment which 
pass under the general name of business, and which, little as we are 
disposed to recognize the fact, bear the same relation to the health 
of the mind that food, exercise, etc., do to the health of the body. 
Work is the condition of our being as active and progressive crea- 
tures. 

420. '' The saddest effects of the absence of stated useful employment 
are seen among women of easy circumstances. It is a poor view of 
woman's duties and capacities that confines her to a little busy 
idleness because the chances of fortune have placed her beyond 
the necessity of earning a living, and they must have but a narrow 
view of the exigencies of social life who believe that any w^oman 
of tolerable health and strength may not find abundant opportu- 
nities of that kind of work which affords no other recompense than 
the consciousness of doing good, and therefore to be done, if done 
at all, by those who can dispense with every other compensation. 
A life of idleness and luxurious ease can be no more honorable to 
one sex than to the other, and we know very well that in a man it 
creates no claims upon the respect and confidence of the com- 
munity." 

421. XoRMAL Sleep. — In sleep the prominent feature 
is the cessation of the automatic activity of the brain. All 

421. "What is the chief feature of sleep ? What has been observed ? 
What is Pfliigei-s idea? 



THE NERVOUS SYSTEM. 237 

parts of the body share directly or indirectly in it; the 
pulse and respirations are slower; the intestines and the 
viscera are more or less at rest ; the secreting organs are 
less active, and the temperature of the body is lowered. 
During sleep the cerebral vessels do not appear as gorged 
as during the waking hours. It cannot at present be stated 
what is the determining cause of this rise and fall of cere- 
bral activity. Pfliiger suggests that the marked inter cpis- 
sion in brain-activity is due to an exhaustion of the oxygen 
stored up between the brain-cell molecules; that sleep is 
necessary for the maintenance of the functions of the 
brain; that during sleep the cerebral tissues lay up new 
stores of oxygen and other foods, in order to compensate 
for the disintegration and waste of the active hours. Sleep, 
after a day's labor, is deepest at its commencement. 

422. The early hours of night afford the most refreshing sleep. 
The ventilation of the sleeping-room demands attention every 
night (207). The amount of sleep needed depends upon the age, 
health, natural temperament, and occupation of the individual. 
Pichegru is said to have slept only four hours out of twenty-four 
during one year's campaign. John Hunter, the anatomist, and 
Frederick the Great, required only five hours daily. The young 
and the aged need more sleep than the person of middle life; the 
sick, more than the well ; those engaged in mental pursuits, more 
than those wearied by manual labor ; persons of great sensibility, 
more than the sluggish natures whose normal condition is more 
nearly allied to sleep ; women more than men. We may say, in 
general, that the time should not be less than from six to eight 
hours. Most persons, however, require a longer period. 

423. BpvAIN-Work. — All good brain-work is accom- 
plished by a brain having a reserve of strength sufficient 
to give buoyancy to the work. Thoroughly agreeable 

423. What conditions are essential for good brain-work ? What 

of the well-trained brain? Of the ill-trained? 



238 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

mental work stimulates the recuperative faculty of the 
centres, and the supply of impulses seldom fails. In 
healthy centres the reserve of energy is kept up, and the 
brain increases in power for work and for endurance. The 
well-trained brain can do immense amounts of work and 
keep its condition ; an ill-trained or non-trained brain, 
under less work, will give way. The condition which 
most commonly exposes the reserve of mental energy to 
loss is worry. It is not mental work, but worry, that 
uses up the brain. 

424. Worry largely arises through the feeling of in- 
capacity to perform the work at hand. By the wearing 
influence of worry the tone and strength of the mind are 
seriously impaired. As a result of worry, the nerve-mech- 
anisms are thrown out of gear, and brain-action becomes 
discordant, and even painful. In school-life, the '^ cram- 
ming" of facts, the straining of the memory, the rivalry for 
prizes, the desire to do three years' work in two, with the 
lurking fear of failure before the mind ; and in world-life, 
the struggles, the strifes, the combinations in business and 
in social circles, the envyings and emulations, constitute 
sources of worry. The induced abnormal cerebral action 
is manifested by headaches, confusion of thought, inability 
to fix the attention, failure of the memory, sleeplessness, 
and even pain. The impairment or failure of cerebral 
action indicates the need of hrain-rest. 

425. Rest (529). — This is best secured by change of 
occupation. Idleness is the worst method of attaining rest. 
To a young person suffering from continuous headache, or 

424. What is the cause of worry ? What results from worry ? 
Mention some sources of worry. "What are indications for rest ? 

424, How can brain-rest be secured ? What of idleness ? In 
normal action ? How with the laborinjr classes ? 



THE NERVOUS SYSTEM. 239 

from wakefulness, moderate daily out-of-door work, not 
drugs, is indicated. All studies should cease. Amuse- 
ment and muscle-work should occupy the waking hours. 
Only by a radical change can permanent cerebral mischief 
be averted. When the brain-action is normal, and no 
inconvenience is felt, mental rest may be secured daily by 
some kind of mental work which, without being fatiguing, 
requires just enough effort to impart interest, as a change 
from mathematics to languages or literature, or from these 
to music, painting, etc. Rest of the best kind is often 
afforded by diverting excursions and amusements. Among 
the laboring classes, amusements constitute almost the only 
practicable means for repairing the constant waste of ner- 
vous energy incident to monotonous toil and daily worries. 



CHAPTEE XIL 

THE SPECIAL SENSES. 
Taste. 

426. The tongue (251), seated in the mouth, bears the 
chief end-organs of the sense of taste. The special nerves 
of taste are portions of the fifth and ninth cranial nerves 




Fig. 90 {Dalton). Diagram of the Tongue, with its sensitive nerves and papillae.— 
1, Lingual branch of fifth pair. 2, Glosso-pharyngeal nerve. 

(382), which end in the papillae of the mucous membrane 
of the tongue and palate. Minute blood-vessels, as well 
as nerves, pass into these papillae. (See fine print under 
251.) 

427. Physiology of Taste. — It is essential for the 
development of taste that the substance experimented upon 

426. "What are the nerves of taste? "What end in the papillae? 

427. What is essential for the development of taste? How is the 
sensation increased ? "When is it most acute ? 

240 



THE SPECIAL SENSES. 241 

should be dissolved. The effect is increased by rubbing 
the solution between the tongue and some hard body, as 
the roof of the mouth. The larger the surface, the more 



Fig. 91. 




intense the sensation. 
A temperature of 22° 
C. (72° F.) is most 
favorable for the de- 
velopment of the sen- 
sation. Temperatures ^ 
much above or below ^'^- ^^ ^^'''^'^- ^'^''^''^ °^ ^"^ ^^^^^^^ «^ ''"'^ 

iiiuv.li auKj\K: KjL uciuw Tongue, moderately magnified.— 1, Capitate papilla. 
this lessen the Sensa- 2, Conical papillae. 3, Epithelium. 4, The same 
, . c^, . , , structure forming bunches of hair-like processes. 

tion. Sw^eet substances 5^ ^.^oiar tissue. 

have most effect when 

placed on the tip of the tongue ; bitter, when placed on the 

back ; and acid, it is said, on the edge. 

428. Tastes may be classified as acid, saline, bitter, and sweet. 
Substances have the power of affecting the taste end-organs by 
virtue of their chemical nature. When the tongue is tapped, or a 
constant current is passed, a taste-sensation arises in the brain. 
The taste-sensation takes some time for its development after con- 
tact of the sapid body. Vintschgau determined the " reaction 
period" to be — for salines, .1598 second ; for sugar, .1639 second ; for 
acids, .1676 second ; and for quinia, .2351 second. Von Wittich 
found it to be .1670 second for the constant current. The sensation 
endures for a considerable time, though this may be due to the sub- 
stance remaining in contact. 

Smell. 

429. The end-organs concerned in the sense of smell 
are the nerve-filaments coming from the olfadori/ lobes 
(362). The nerve-filaments are distributed to the mucous 

429. Speak of the end-organs concerned in smell. Describe the 
nasal passages. AVliat of the membrane? Of the olfactory nerves ? 
Of the fifth pair ? 

L (7 21 



242 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



membrane lining the upper nasal passages. The nasal 
passages (see Fig. 38) extend from the opening of the nos- 
trils in front to the pharynx behind. They are high, 
vaulted, narrow, and are separated from each other by a 
median partition, partly bony and partly cartilaginous. In 

the upper part of the 
vault are plates of bone 
hanging from the body 
of the ethmoid bone of 
the skull, and in the 
middle part a pair of 



Tig. 92. 




Fig. 92. A Transverse Vertical Section 
OF THE Bones of the Face. — 7, Middle turbi- 
nated bone. 8, 8, Ethmoidal cells. 10, 10, In- 
ferior turbinated bones. 11, Vomer, covered by 
nasal mucous membrane. 14, Antrum. 17, 
Floor of nostrils and roof of mouth. 19, Mu- 
cous membrane of roof of mouth. 18, Anterior 
alveolar arch. 



scroll-like bones, the tw- 
hinated. Over these is 
stretched the very vascu- 
lar nasal mucous mem- 
brane. The horizontal 
plate of the ethmoid, on 
which rest the olfactory 
lobes, has many holes, 
through which pass the 
nerves of smell. The 
nerve of sensation to the 
nasal mucous membrane is from the fifth pair. 

430. Physiology of Smell. — The olfactory end-organs 
are the only structures of the body upon which odors have 
a distinct effect. The sensory impulses produced in the 
olfactory end-organs, ascending to the brain, give rise to 
the sensation of smell. For the development of smell- 
impulses, the odorous particles must be conveyed to the 
membrane in a gaseous medium, as of the air. When the 

430. How does the sensation arise ? How are smell-impulses de- 
veloped ? Influence of perfumed water ? 
time ? How is the sense Llunted ? 



Of air? Of sniffing:? Of 



THE SPECIAL SEifTSES. 243 

nostrils are filled with rose-water, the odor of rose is not 
perceived. Each odorous substance causes a specific sensa- 
tion. In ordinary breathing, through diifusion (176), por- 
tions of the incoming and outgoing air reach the olfactory 
end-organs. By sniffing, the odorous air is drawn higher 
up into the nasal passages, and thus influences a greater 
surface. The larger the affected surface, the more intense 
the sensation. We recognize the odor of cologne through 

Fig. 93. 




Fio. 93. A Side- View of the Passage of the Nostrils and the Distribution of 
THE Olfactory Nerve. — 4, The olfactory nerve. 5, The fine divisions of this nerve on 
the membrane of the nose. 6, A branch of the fifth pair of nerves. 

the olfactory nerve, and the pungency of ammonia through 
the fifth nerve. Time is required for the development and 
transmission of the impulses, and the sensation continues 
for some time. Under the constant influence of an odor 
or odors, the olfactory impulses are not perceived in the 
brain. This blunting of the sense of smell is noticed after 
remaining several hours in an atmosphere vitiated by 
tobacco-smoke and i)ulmonary and cutaneous exhalations, 
then going into the outer air and, after a few minutes, re- 
turning to the room. Hence it is that escaping gas and 
entering sewer-gas often fail to awaken the deep sleeper. 



244 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Audition. 
431. The apparatus concerned in hearing consists of three 
parts, — the external ear, Fig. 94, 1 ; the middle ear. Fig. 
94, 2 to 6 ; and the internal ear, Fig. 94, 6 to 13. 

Fig. 94. 




Fig. 94. A View of all the Parts of the Ear. — 1, Meatus, or canal. 2, The mem- 
brana tympani. 3, 4, 5, The b'ones of the ear. 6, Membrane of the foramen ovale. 
7, The central part of the labyrinth (vestibule). 8, 9, 10, The semicircular canals. 11, 
12, The channels of the cochlea. 13, Auditory nerve. 14, The opening from the middle 
ear, or tympanum, to the throat (Eustachian tube). 

432. The External Ear consists of the jpinna and 
the external auditory meatus, or canal. The pinna is made 
up of a framework of firm, elastic cartilage, covered with 
skin, and attached to the sides of the head. It is provided 

431. Of what is the hearing apparatus composed ? 

432. Describe the pinna. What of its muscles ? Describe the 
meatus. What of its lining ? 



THE SPECIAL SENSES. 245 

with three feeble muscles, which in some persons are suf- 
ficiently developed to cause the movements of the pinna. 
The meatus is a bony and cartilaginous canal, lined with 
skin, leading to the interior of the temporal bone (Fig. 73). 
It is about one and one-quarter inches deep, and terminates 
at the tympanum. Its lining skin holds many stiff hairs, 
nunierous glands, which secrete a wax (cerumen) having a 
bitter taste, and a few oil-glands. 

433. The Middle Eae, or Tympanum, is a small" 
chamber in the temporal bone. It contains air, certain 
small bones, a few minute muscles, and nerves. It is sepa- 
rated from the meatus by a thin, oval-shaped membrane, 
called the membrana tympani. It is lined with mucous 
membrane. It communicates with many bony cells of the 
temporal bone, with the internal ear by two openings, 
which are closed in the natural state with membranes, and 
through the Eustachian tube with the pharynx (158). 
Hence, in catarrhs of the nasal passages and of the 
pharynx, the disease-process often extends np the tube, 
involves the middle-ear membrane, and gives rise to pain 
and deafness. The bones are three in number, — the mal- 
leus (hammer), the incus (anvil), and the stapes (stirrup). 
These bones weigh only a few grains, are covered with peri- 
osteum, have blood-vessels and nerves, give attachment to 
minute muscles, and form movable joints. 

434. The malleus is attached by its projecting process, called "the 
handle," to the inner surface of the membrana tympani, and the 
rounded part, or " head," is articulated with the thick part of the 
incus. By its short leg the incxs is attached to the hack wall of 
the tympanum, and hy it« long leg to the stapes. The ufaprs has a 

433. What is tho rniddlo. oar? Its contontii? Tt?! meinhrnnc ? 
Openings in the middle (>!ir? Tiu> Kustju'hian tubo? AVliat oi' 
catarrhs? Spcidc of the small btmos oi' \ho oar, 

21^- 



246 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



remarkable resemblance to an iron stirrup. The foot-piece of the 
latter is attached to the membrane which closes the fenestra ovalis, 
or opening into the internal ear. These bones are so articulated to 
one another as to act as a single lever, the fulcrum being at the junc- 
tion of the short leg of the incus with the wall of the tympanum, 
the long arm being in contact with the membrana tympani, and the 
short arm terminating in the base of the stapes. Hence the move- 
ment of the stapes is less than that of the membrana tympani. 

Fig. 95. 




Fig. 95. A View of the Labykixth Laid Open.— 1, 1, Cochlea. 2, 3, Two canals, 
that wind two and a half turns around a hollow axis (5). 7, Vestibule. 8, Fenestra 
rotunda. 9, Fenestra ovalis. 11, 12, 13, 14, 15, 16, 17, 18, The semicircular canals. Highly 
magnified. 

435. The Inteenal Ear, or Labyrinth, consists of 
several complex chambers and canals, each containing mem- 
branous and fluid contents and nerve-endings. The spaces 
occur in the hardest part of the temporal bone, in the base 
of the skull. These spaces communicate with one another. 



435. What is the labyrinth? In what bone seated? What open- 
ings has it? Describe the chambers. Speak of the end-organs. 



THE SPECIAL SENSES. 



247 



Fig. 96. 




also with the middle ear, by two openings, the fenestra 
ovalis and the fenestra rotundum, and internally with the in- 
ternal auditory meatus, which transmits the nerve of hearing 
from the brain to these spaces. These chambers consist 
of the oval-shaped vestibule, 
the three bony tubes of 
the semicircular canals, and 
a spiral, bony canal making 
two and a half turns, the 
cochlea, or ^'snail-shell/^ 
The end-organs of the audi- 
tory nerve are of two kinds, 
— the complicated organ of 
Corti, found in the cochlea, 
and the epithelial arrange- 
ments of cells and hair-like 
organs in the vestibule and 
the canals. 

436. Sound, as sound, has no existence in nature. It 
cannot exist independent of a sense of hearing. When a 
tense string or wire, or a bar of steel, is struck, it is thrown 
into vibrations. These vibrations communicate movements 
to the adjacent air, water, or solids. The latter vibrations, 
conveyed to the end-organs of the ear, develop certain im- 
pulses. These impulses, reaching certain brain-centres, give 
rise to the sensation of somid. If the vibrations are less 
than eight per second, or more than thirty-eight thousand 
per second, the sensation of sound is not perceived by man. 
The range of ordinary appreciation of tones lies between 
forty and four thousand vibrations per second. 



Fig. 96. A View of the Auditory Nerve. 
— 1, Spinal cord. 2, Medulla oblongata. 3, 
Lower part of the brain. 4, Auditory nerve. 
5, A branch to the semicircular canals. 6, A 
branch to the cochlea. 



43G. Whut is necessary for the cxistonoo of sound? How is sound 
produced? How transmitted? How does the sensation arise ? AVhat 
of the appreciation of sound ? 



248 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

437. Sounds cannot be produced in, or propagated through, a 
vacuum. To produce or to transmit sound there must be some 
matter, as air, water, or solids, to be thrown into vibration. In 
musical sounds, the vibrations which cause them are periodical. 
When the vibrations are irregular, or the period is so complex as 
not to be appreciable, then the sensation produced is that of a 
7ioise. The human ear appreciates best the sound- vibrations which 
are transmitted through the air. It can and may receive sounds 
by the mouth and the nasal fossae through the Eustachian tube, as 
when a vibrating tuning-fork is held between the teeth. 

438. Functions of the Exteenal and Middle 
Eaes. — The pinna collects the waves of vibrations coming 
from various directions, and directs them into the meatus, 
and thence on to the memhrana tympani. This membrane is 
very susceptible to air-vibrations, and is most readily thrown 
into corresponding movements when sound-waves reach it 
by the meatus. The loose articulation of the ear-hones pre- 
vents good bone-to-bone transmission of vibrations. But the 
series of bones acting together as one lever (434) transmits 
every vibration of the membrana tympani to the membrane 
covering the opening — fenestra ovalis — to the internal ear. 
The movements of the internal ear membrane are less than 
those of the membrana tympani, but the loss in amplitude 
is made up by a gain in force. Thus the sound-wave vibra- 
tions are intensified at the entrance to the labyrinth. The 
Eustachian tube, by permitting air to enter or to leave the 
middle ear by way of the pharynx, admits of equal press- 
ure on the outer and inner surfaces of the membrana tym- 
pani. This arrangement, like the air-hole of a drum, 
enables the membrane to work equally well in the rare air 
of the mountain-top and the dense air of the deep mine. 



438. What is the function of the pinna? Of the membrana tym- 
Of the Eustachian tube ? 



THE SPECIAL SENSES. 249 

The tube also permits the secretions of the membrane of 
the middle ear to escape to the pharynx. 

Experiment. — Close the nose and lips, fill the mouth-parts, and distend the cheeks 
with air, then go through the act of swallowing, but do not allow the air to escape by 
the mouth. After some practice, a peculiar pressure will be felt in both ears. Air has 
thus been forced from the pharynx through the Eustachian tube into the middle ear, 
and the membrane is forced outward. This sensation continues until, by the act of 
swallowing, the excess escapes. The aurist, by entering a peculiar tube into the Eusta- 
chian tube through the nostrils, is enabled to force air into the middle ear, and thus 
influence the membrane. 

Close the mouth and nose, then, at the same time, swallow and inspire. Air will be 
drawn out of the middle ear, the membrane becomes drawn in, and a feeling of tension 
is produced. During the presence of an abnormal amount of air, or absence of a normal 
amount, the power of hearing is impaired, because the membrane cannot perform its 
normal function. If a person goes frorn the outer air at once into the condensed air of 
a caisson, there is great danger of the membrane being ruptured, owing to the unequal 
pressure. The same may be effected on coming out of the caisson, by reverse pressure. 

439. Physiology of Hearing. — The pinna, the me- 
atus, the membrana tympani, the middle-ear cavity, the 
Eustachian tube, and the chain of bones, all work together 
to facilitate the reception of vibrations from without, and 
to transmit them correctly to the interior. This is their 
only function. The vibrations of the membrane at the 
base of the stapes are communicated to the fluids in the 
vestibule. The vibrations of this fluid are transmitted to 
the fluid in the cochlea and to the fluid and calcareous 
bodies within the membranes of the vestibule and semicir- 
cular canals. The physiological process of hearing only 
commences in the labyrinth. The end-organs of the audi- 
tory nerve in the labyi-inth receive modified vibrations and 
generate auditory impulses. These impulses, passing over 
the auditory nerve and reaching certain parts of the brain, 
induce what we call auditory sensation. The appreciation 
of sound-waves is ultimately a mental act. 

439. What parts serve only to transmit? By what are vibrations 

transmitted in the liihvrinth ? Where do the auditory impulses arise? 
Where the auditory sensations ? 



250 

440. Whenever the fibres of the auditory nerve are stimulated, 
either by vibrations through the proper end-organs or by the direct 
application of stimuli, — electrical, chemical, or mechanical, — the 
result is always a sensation of sound. If sound-waves fall on the 
auditory nerve, they produce no sensory effect. Experiment shows 
that sound-waves must be brought to the auditory filaments through 
the proper end-organs to occasion in the brain the sensation of 
sound. The vibrations generated in the fluid, the endohjmph, within 
the membranous canals and vestibule, are supposed to influence the 
auditory hairs and cells ; the vibrations of the vestibular fluid, the 
perilymph, to influence the organs of Corti and the basilar mem- 
brane. Certain structures of the membranous semicircular canals 
are held to be the end-organs of the sense of equilibrium (475), and 
the organ of Corti is considered to be the end- organ of the labyrinth 
concerned in the sense of hearing. 

441. Auditory Sensations.— They are of shorter duration than 
visual sensations. When a visual sensation is repeated ten or more 
times a second the sensations become fused as one (463). The ticks 
of a pendulum beating one hundred a second are audible as distinct 
sounds. A well-trained ear can distinguish, through a long range 
of notes, the difference of a single vibration per second. The " re- 
action period" for sounds is about one-sixth of a second. In seek- 
ing for the cause of auditory sensations, we almost always refer 
them to the external world. We do not think of the sound as 
originating in the hearing apparatus. The judgment of the distance 
of sounds is quite limited. A sound of a known character we locate 
as near or far by its degree of loudness. The distance through 
which an unaccustomed sound has been propagated we can only 
vaguely surmise. The judgment of direction of sounds is also 
limited. In determining direction, the position of the head and 
the ear most affected are chiefly to be depended upon. The origin 
of the sound from the human voice is found to be more readily and 
accurately located than the vibrations from a musical instrument 
or from noise. 

Sight. 

Directions for Dissection. — Secure the eye of an ox or sheep. Observe: the trans- 
parent, bulging, glass-like cornea in front ; surrounding and continuous with the cornea, 
the dirty -white sclerotica ; and the thin conjunctiva adherent to tlie sclerotica as far for- 
ward as the corneo-sclerotic junction, and as far back as the junction of the eyelids with 
the ball, and on the inner side of the lids. Dissect away the fat from the posterior part 



THE SPECIAL SENSES. 



251 



of the ball, exposing the junction of tlie four recti (straigtit) muscles with the sclerotic 
and the round ojptic nerve. The latter does not enter the ball in the axis of the eye. 

Puncture the cornea, and a small amount of limpid fluid, the aqueous fluid, escapes. 
With fine embroidery scissors cut the cornea from the sclerotic close to its union with 
the latter. The cornea is seen to be "transparent, of nearly uniform thickness, .and 
watch-glass-shaped. With the cut surface uppermost, examine the eye. Note : the 
iris, its free edge bounding the dark opening called the impil, and resting on the anterior 
surface of the capsule of the lens. On the front surface of the lens make a shallow, 
cross-ehaped incision. The tissue which retracts is the caj)sule of the lens. Under slight 



Fig. 97. 




Fig. 97 {Leidij). Muscles of the Eyk.— 1, The palpebral elevator muscle. 2, The 
superior oblique. 3, The pulley through which the tendon of insertion plays. 4, Supe- 
rior straight iuuscle. 5, Inferior straight muscle. G, External straight muscle. 7, 8, 
Its two points of origin. 9, Interval through which pass the oculo-motor and abducent 
nerves. 10, Inferior oblique muscle. 11, Optic nerve. 12, Cut surface of the malar pro- 
cess of the superior maxillary bone. 13, The nasal orifice. A, The eyeball. 



pressure with the haiulle of the scalpel the le)is will escape from its capsule. Notice the 
diiference in curvature between its front and rear surfaces, the firmness of its tissues, 
and its transparency. Cause a ray of light to jiass through a fresh Ions, and note its 
refraetiiKj power. Behind the bed in which the lens rested will be seen the glassy ritn'oits 
humor. Allow the vitreous to escape. Looking into the hollow of the ball, note: the 
entrance at the fundus of the optic ncm; and the blood-vessels radiating from that spot. 
Separate the inner thin membrane, the relitia, from the next membrane, the choroid. Ob- 
serve that the retina appears like an expansion of the optic nerve, and that most of tho 
black pigment adheres to the choroid. At tlu< anterior edge of the choroid, near its junc- 
tion with tho cornea, are sei^n the pale llbres of (lie ciliuri/ mim'h: Outside of the choroid 
is seen the sclerotica of the posterior part of the ball. 



252 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Microscopic Work. — The careful examination of the eyeball is one of the most re- 
munerative labors of the microscopist. The study of the retina, however, is one of the 
most difficult problems. The fresh, still warm eyes of the ox or sheep are best. The 
injection run into the optic artery is preferably carmine or Prussian blue. In half an 
hour the work of dissection and examination may be commenced. Make transverse 
sections of the cornea and sclerotica. Tease out and examine in five per cent, saline 
solution or the aqueous humor bits of the various membranes. By such work much can 
be learned of the structure of the organ. The transparent structures require to be hard- 
ened and darkened, in order to make out the relations of one structure to another. (For 
details see Frey's " Microscopic Technology," Section 22.) Miiller's eye-fluid— bichro- 
mate of potassa, 2 grammes ; sulphate of soda, 1 gramme ; distilled water, 100 grammes — 
is excellently adapted for hardening the unopened immersed eyeball. After a month's 
immersion, very handsome and useful sections can be made. 

442. The Organs of Sight in man consist of the eye- 
halls. The external protective apparatus consists of the 
eyebrows, the eyelids, the lachrymal gland and its append- 
ages, and the palpebral glands. The ej^eballs and the tear- 
glands are lodged in the bony cavities called the orbits, 

443. The Orbits are pyramidal in shape, having a 
quadrangular base. Their apexes are directed backward 
and inward. Near the apex of' each orbit may be seen 
openings for the nerve of sight, the nerves of sensation 
and motion of the eye-parts and blood-vessels. In the 
orbit the eyeball rests on a cushion of fat, and is moved 
by the ocular muscles, — four straight muscles (recti) and 
two oblique (superior and inferior obliquus). 

444. The Eyebrows are the thick, fat ridges, studded 
with hairs, surmounting the orbits. The hairs are set 
obliquely outward. The Eyelids are the two thin, mov- 
able covers of the eyeball. The upper one is the larger, 
and provided with a special elevator muscle. The free mar- 
gins of the lids are bevelled and beset with eyelashes. The 

442. What are the organs of sight ? Name the protective organs. 

443. Describe the orbits. Upon what do the eyeballs rest ? How 
moved ? 

444. Describe the eyebrows. The eyelids. The eyelashes. The 
palpebral glands. 



THE SPECIAL SENSES. 



253 



lashes of the upper lid curve upward, those of the lower, 
downward; hence there is no interlacing. Each eyelid 
consists of a thin, semilunar plate of cartilage, covered 
on the outside with thin skin and fibres of the muscle of 
the lids [orbicularis palpebrarum, Fig. 127), and on the in- 

FiG. 98. 




Fig. 98 {Leidy). The Left Evelid and LAcriRVMAL Gland, .turned Forward and 
Inward, to show their Inner Surface.— 1, Upper and lower part of the orbit. 2, 
rortion of the palpebral orbicular muscle. 3, Attachment of this muscle to the inner 
margin of the orbit. 4, Perforation for the passage of the external nasal nerve. 5. Offset 
described as the tensor muscle of the eyelids. 6, Palpebral glands. 7, Posterior, and S, 
anterior portions of the lachrymal glands. 9, 10, Ducts. 11, Orifices opening on the 
inner surface of the upper eyelid. 12, 13, Puncta lachrymalis. 

side with the conjunctiva (448). On the inner surface of 
the cartilage are little grooves, which contain the minute 
palpebral glands. The oily secretion from these glands 
passes by minute ducts on to the free edge of the lids. 

445. Functions. — The cyebroios influence the amount 
of light reaching the eyes, slightly protect the eyeballs 



445. What arc tho functions of the eyebrows? Of the lids and 
hishes? Of the palpebral g-lands? 



254 



Fig. 99. 



from foreign bodies, and tnrn aside the perspiration flow- 
ing from the forehead. The eyelids and lashes prevent the 
entrance of an excess of light, and, by the rapid movements 
of the former, play an important part in the moistening 

and cleansing of the eyeballs. 
In winking, which may be vol- 
untary, though usually reflex 
(82), foreign bodies are swept 
over the ball inward to the 
lachrymal lake. The palpebral 
gland secretion oils the edges of 
the eyelids, prevents their adhe- 
sion, and protects them from the 
action of the tears. 

446. The Lacheymal 
Gland (Fig. 99) is a small 
almond-shaped body, found in 
a depression in the upper and 
outer part of the orbit, between 
the bone and the eyeball. Its 
ducts, from six to twelve in 
number, open on the inner sur- 
face of the upper eyelid, near the outer angle. Their 
secretion, the tears, is a clear, saltish, alkaline fluid, con- 
taining a little albuminoid matter. 

447. Lachrymal Canals. — On the margin of each 
eyelid, near the inner angle, is a little projection, having a 
small opening, the punda lachrymalis. This is the com- 
mencement of the tear-canal. The short canals from the 




Fig. 99. View of Lachrymal 
Gland and Nasal Duct. — 1, The 
lachrymal gland. 2, Ducts leading 
from the lachrymal gland to the 
upper eyelid. 3, 3, Canaliculi. 4, The 
nasal sac. 5, The termination of the 
nasal duct. 



446. Speak of the lachrymal gland. Shape. Location. Duct- 
secretion. 

447. What is the puncta? What meet in the nasal sac? 



THE SPECIAL SENSES. 



255 



puiicta of the upper and lower lids meet in the nasal sac, 
from which the nasal duct conducts the tears to the lower 
part of the nose. 

448. The Conjunctiva is a mucous membrane (165). 
It lines the inner surface of the lids, covers the exposed 
surface of the eyeballs, . „ 

dips into the orifices of 
the glands, and, through 
the nasal duct, is continu- 
ous with the nasal mem- 
brane. Hence, in colds 
of the nasal passages, the 
eyes are often red, irrita- 
ble, and watery. 

449. Functions. — The 
secretions of the lachrymal 
glands and of the con- 
junctiva moisten the sur- 
face of tlie eyeballs and 
lids, facilitate the move- 
ments of the eyeball, and 
preserve the transparency 
of the cornea. The tears 
are the more abundant 
secretion. An increased 
flow of tears may be oc- 
casioned by a strong light, by irritants acting on the 
faces of the eye, nose, and tongue, as of dust, snnif, and 
pepper, and by vomiting, laughing, and crying. By con- 
stant efforts, the tear-glands can be educated to i)roduce 

448. Describe the conjunctiva. What occurs in C(»lds ? 

449. What are the functions ot" the tears and mucus? How may 
the tear-flow he increased? AVhat hccomcs ot" the tears? 




Fig. 100. The Second Pair of Nerves. — 

1, 1, Globe of the eye: the one on the left is 
perfect, but that on the right has the sclerotic 
and choroid coats removed, to show the retina. 

2, Optic commissure. 5, The pons Varolii. 6, 
The medulla oblongata. 7, 8, 9, 10, 11, 12, 13, 
The origin of several pairs of cranial nerves. 



ur- 



256 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

large amounts of tears, as seen in lachrymose beggars, 
hypocrites, etc. In passing over the surface of the eyeball, 
a portion of the secretions is evaporated, but the larger 
part passes into the punctse of the lids and is discharged 
into the nostrils. When mental emotions excite a flow of 
tears, the lady removes the surplus from the eyes and face 
with her handkerchief; but the gentleman, not wishing 
that his emotion should be marked, covers his face with 
his handkerchief — and blows his nose. 

450. The Eyeball is a strong, closed, membranous sac, 
rudely compared to a globe. It is about an inch in diam- 
eter. It is spherical in form, but has a segment of a smaller 
and more prominent sphere engrafted on its front part. 
Hence its front-to-rear diameter is longer than its side-to- 
side diameter. It is attached behind to the optic nerve, and 
is maintained in position by its muscles (443). It occupies 
a protected position in the orbit, and has an extensive range 
for vision. The optic nerves arise each on its side of the 
brain, but at the commissure (Fig. 84, 24) they communi- 
cate with each other. 

451. Membeanes or Tunics. — The eyeball is surrounded 
by a hard, firm membrane, the sclerotica (Fig. 101, m, n). 
In living persons, the front exposed segment of this mem- 
brane sliining through the conjunctiva, /, /, is called the 
" white of the eye." In front it passes into the cornea, 
h, h, characterized by its glass-like transparency. It rises 
and bulges in the middle, like an old-fashioned watch- 
crystal, and through it light passes into the interior. 
Within the sclerotica is a thinner and more delicate mem- 

450. Describe the eyeball. What of its position ? What of its 
nerve ? 

451. Speak of the sclerotica. Of the cornea. Of the choroidea. 
Of the iris. Of the retina. 



THE SPECIAL SENSES. 



257 



brane, the Ghoroidea, g^ g. It contains a large number of 
blood-vessels, and is black, owing to the presence of a large 
number of pigment-cells. This membrane joins in front 
the ms, j9, p, which is seen to rest on the front surface of 



Fig. 101. 




Fig. 101. Horizontal Section of Right Eye (from HchnhoU::).— ]]', Aqueous humor. 
L, Lens, ri, Vitreous humor. /,/, Conjunctiva. 7;. /*, Cornea, p, p, Iris. /, ^ Ciliary 
muscle, k, ft, Hyaloid membrane, c. Ciliary processes, e, e, Suspensory ligament. 
m, n, Sclerotica, g, g, Choroidea. i, Retina, s, Fovea centralis, d, Optic nerve. 



the lens. This iris is seen in every normal human eye, and 
assumes a lighter or darker hue accordino- to the number of 
its pigment-cells. The iris surrounds the dark opening, the 
pupil. Within the clioroid is an exceedingly delicate mem- 
brane, the rcthid, i It forms the continuation and cxtcn- 
r 22* 



258 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

sion of the optiG nerve, d, the nerve of vision. It contains 
the end-organs of the apparatus of vision. 

452. Iris. — The greater the number of the pigment-cells on the 
posterior surface of the iris, the darker is the " color of the eye." 
The variation in amount of the pigment is the cause of the different 
shades seen in the eye, ranging fi-om the darkest brown to light blue 
and gray. In the albino, the pigment is absent from the choroid, 
as well as from the hair and skin. The iris of an albino appears 
whitish red, and the pupil of a bright red. AVhen exposed to a 
dazzling light, through reflex action, the eyelids are incessantly 
winking, owing to the retinal demand for a moderation of the light. 
The iris is provided with dilating and contracting muscular fibres. 
In the natural state, the pupil is constantly undergoing changes of 
diameter. The instillation of a solution of atrojiia causes the pupil 
to become very large ; of eserina, very small. 

Demonstration and Experiments. — Select a boy having a large ocular fissure and a 
prominent eye. Call the attention of the class to the eyebrotvs, the direction of the hair, 
the thickness of implantation as compared -with some other boys, and the hairless tract, 
in most cases above the bridge of the nose, eyelids, and eyelashes. Point oiit the method 
of the insertion of the lashes, the direction and curvature of the upper and lower rows, 
and the non-interlacement. Gently pull down the lower lid. Demonstrate the junction 
of the mucous membrane and the skin, the place of implantation of the lashes, the fifteen 
to twenty openings on the fine edge of the lid (oiitlets of the palpebral (jlaud ducts), and 
the slight elevation on the margin near the inner angle, which has an opening (puncta). 
Gently seize the lashes of the upper lid, hold a small pencil on the upper lid from three- 
eighths to five-eighths of an inch from the margin, direct the student to look down, then 
quickly evert the lid. Note the pink, moist mucous membrane, the conjunctiva, and the 
outline of the tarsal cartilage pressing on the conjunctiva. 

W'hen the eye is open, an elliptical space, the fissure, and at the outer and inner junc- 
tions of the skin of the upper and lower lids, the canlhi, appeal". The fissure is almond- 
shaped in the pure Semites, large in negroes, and small in Mongolians. In the Esqui- 
maux, Chinese, and most of the Japanese, the internal canthus is lowered, while the 
external has an upward direction. The internal canthus is covered by a fold of loose 
skin. This fold is slightly stretched over the angle of the eyelids, and covers the carun- 
cle, which is visible in the Americo-Europeans, and forms a kind of third eyelid, in the 
form of a crescent. The small triangular space at the inner canthus, the lacus, contains 
a small, reddish, conical body, the caruncle. This is the source of the whitish secretion 
which collects at the inner angle. 

Point out the loose, clear, white, thin conjunctiva overlying the sclerotica; the white 
or yellowish-white sclerotica, the clear, transparent cornea, the black pujnl, and the vari- 
ous-hued iris. Place a lamp to the right and a little in front of the face of the student. 
With a convex lens between the lamp and the 'eye, direct a pencil of rays on to the 
cornea. Then call attention to the cornea, its form and sclei'al junction, the anterior 
chamber, containing the aqueous humor, the iris, and the lens. Note the ready contraction 
and dilatation of the pupil under varying amounts of light. 



THE SPECIAL SENSES. 259 

Request, if convenient, an oculist to demonstrate to the class the fundus of the eye 
from the normal model of the phantom, pointing out the retinal vessels, the blind spot, and 
the 7jelloiv spot. Then, if possible, permit the students to observe the interior of the living 
eye by the aid of the ophthalmoscope. 

Look with one eye intently through a small hole in a card at the bright blue sky. 
Move the card very rapidly from side to side, or up and down. The eye sees on the cards 
the shadows of the fine capillary retinal vessels. Hence the end-organs of the retina 
are behind the blood-vessels (462). Remove the objective from a microscope. Look into 
the eye-piece, and move the head rapidly from side to side, when the shadows of the 
retinal vessels will be perceived by the eye. 

Close the left eye. Hold a sheet of white paper having a central black dot before the 
right eye. Fix the eye on the black spot. Dip a quill-pen in black ink, and move its 
point gradually in one direction from the black spot. At a certain distance, the black 
spot of ink will no longer be seen. Make a dot. Continue the movement outward, and 
the ink-spot again comes into view. Make a dot. It will now continue in sight until it 
passes from the field of vision. Make similar trials along other meridians. Connect the 
black places by lines. An irregular figure will be drawn, circumscribing an area of the 
field of vision within which rays of light produce no visual sensation. This indicates 
the presence of a blind spot in the eye (462). 

453. Functions of the Tunics. — The sclerotica and 
cornea determine the form of the eyeball, and support and 
protect the delicate parts in the interior. Through the 
posterior part of the former pass the optic nerve and the 
retinal vessels, and into it are inserted the muscles which 
move the eyebalL The former is not transparent, but a 
strong light directed through it illuminates the interior. 
The cornea permits the ray of light from the outer world 
to enter the eye. The choroidea absorbs the stray rays 
of light, and thus assists in making a clearer image on 
the retina. The iris, by changing the size of the pupil, 
regulates the amount of light entering the eye, acts as a 
diaphragm to cut off the rays which are not parallel to the 
principal stream of light, and aids in near vision. The 
retina contains the microscopic rods and cones, the end- 
organs of vision. The end-organs change the impressions 
of light into the impulses which occasion in the brain the 
sensation of vision. 



453. Wlint. !irc tho functions of tlio soKM-otioii? Of the cornoa ? Of 
the choroidoii? Of iho iris? Of the retina? 



260 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



454. Media and Lens. — The space between the pos- 
terior surface of the cornea and the anterior surface of the 
lens and iris is filled by the aqueous humor , W (Fig. 101). 
This humor consists of about five drops of a limpid fluid 
resembling water. Directly behind the iris is the lens, X, 
which resembles a thick burnino:-p:lass. In the normal 
eye it is clear as crystal. In the disease called cataract it 
becomes more or less opaque. The lens is more bulging, 
or convex, on its rear surface than on its front surface. It 
is enclosed in the capsule of the lens, which is held in 
place by an elastic membrane, the suspensory ligament, e, e. 
The space, spheroidal in shape, between the back surface 
of the lens and the front surface of the retina is filled by 
the vitreous humor, G. This is a clear, gelatinous mass, 
surrounded by a fine thin membrane. 

455. Functions of the Media and Lens. — The eye 
is a camera. It consists of a series of lenses and media 
arranged in a dark chamber, in Avhich the iris acts as a 
diaphragm. The object of this apparatus is to form on 
the retina a distinct image of objects placed before the eye. 
The rays of light on entering the eye traverse in succession 
the cornea, the aqueous humor, the lens, and the vitreous 
humor. The rays of light are strongly bent out of their 
course — i.e., are refracted — at the front surface of the cornea 
and at the front and rear surfaces of the lens. The many 
rays of light coming from the field of view are thus con- 
centrated on the limited field of the retina. 

Experiment.— Remove the front convex lens from a pair of opera-glasses, or procure 
a convex lens with a gradual curve. Hold it opposite a window, and place a piece of 
white paper behind it to act as a screen. A small reversed picture of the window-frame 

454. "Where is the aqueous humor found ? Speak of the lens. How 
is it held in place? Describe the vitreous humor. 

455. What is the eye? What is its function? Through what do 
rays of light pass ? How are they influenced ? What results ? 



THE SPECIAL SENSES. 261 

will appear on the paper. If the paper he moved to a certain distance, varying with each 
lens, the picture will become clear and distinct, yet with color-rings about the edges. At 
that distance from the lens the jjaper is said to be in focus. If the i^aper be moved nearer 
to, or farther from, the lens, the picture becomes blurred, and the paper is said to be out 
of focus. 

Visit a photographer's studio. Bequest him to point out and name the uses of the 
essential parts of the camera, — the blackened box, the ground-glass screen, the lens, the 
diaphragm, and the apparatus for adjusting the lens and the screen to the object. Watch 
him place the camera and then work the ground-glass screen into the proper focus. 
When all is ready, put your head under the curtain of the camei-a and study the reversed 
image depicted on the glass. 

Carefully remove the sclerotica and choroidea from a small portion of the back of a 
bullock's eye, near the entrance of the optic nerve. Place the prepared eye in the end 
of a tube, blackened in the interior, which closely fits the globe of the eye, having the 
cornea forward. You will be enabled to see a distinct reversed image on the retina of 
the illuminated object in front of the cornea. 

456. Light. — The suu is the chief source of light. The 
principal sources of earthly light are combustion, friction, 
and electricity. Bodies which are not luminous, like most 
natural objects, are rendered visible by the light which falls 
upon them. The rays of light move in straight lines. 
The luminous power diminishes as the square of the dis- 
tance through which it passes, — i.e., the illumination is nine 
times as powerful at one foot as it is at three feet from 
the source of light. The sunlight is white. It may be de- 
composed by a prism or a convex lens into several colored 
lights. 

457. Refraction.— When parallel rays of light pass 
from one medium to another, as from air through water 
and glass to air again, in a direction perpendicular to the 
media, they continue to move on in the same lines; if, 
however, they enter the media obliquely, or enter a medium 
having a curved or prismatic surflice, they are bent out 
of their course,— i.e., are refracted. Eays of light coming 

456. Mention sources of lig-ht. How do light-riiys move? How 
does the power decrease? What of sunlij^lit? 

457. Explain tlio phenomenon of refraction of lii;lit. AVliat is its 
connection with clearness of vision ? 



262 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

from a large object and passing through a double convex 
lens, like the lens of the eye, are bent towards the central 
axis of the lens, and form a small reversed image on a 
screen placed behind the lens, but nearer to the lens than 
is the object. If the screen be placed at the focus of the 
lens, the image will be clear and distinct ; if not, the image 
will be blurred. 

458. AccoMMODATioisr. — Whea the photographer has placed his 
camera in a favorable j)Osition in order to secure a clear image on 
the ground glass, he moves the lens, or the screen, or both, back- 
ward or forward until the reversed image of the object appears 
clearly on the glass screen. In the camera the refractive power 
of the lens is fixed, and the diaphragm is changeable, but the dis- 
tance between the lens and the screen is adjustable. In the human 
eye, the distance between the refractive surfaces and the screen 
(retina) is fixed, the diameter of the opening of the diaphragm 
(pupil) and the refractive power of the lens are adjustable. In 
adapting our eyes to form on the retina a clear, sharp image of a 
near object, we are conscious of an efibrt. In this adaptation, — 1, 
the pupil contracts ; 2, the front surface of the lens becomes more 
convex ; and, 3, the refracting power of the lens is thus increased. 
In looking from a very near object to a distant object, no effort is 
needed in the normal eye ; the forced pupil-contraction ceases, and 
the lens assumes its natural shape. Accommodation is the adjust- 
ment within the eye in order to permit a clear and distinct image 
to be formed on the retina. 

Experiment. — In a dark room hold a candle on one side of the ej'e, about eighteen 
inches distant. Let the observer stand on the opposite side of the front of the ej'e. Let 
the examined eye rest at ease. Three images of candle-light will appear, — one from the 
surface of the cornea, an erect image from the anterior surface of the lens, and a reversed 
image from the posterior surface of the lens. If now the person being examined looks 
at an imaginary near object, the first and third images keep their position and rela- 
tive brightness, but the second image advances and becomes dimmer, and the pupillar 
margin of the iris inclines slightly forward. "\Mien the eye is allowed to adjust for dis- 
tant vision, — i.e., assumes the position of ease, — the second inmge recedes and becomes 
brighter, and the others retain their position and relative brightness. Hence, in accom- 
modation, the anterior surface of the lens becomes more convex, the cornea does not 
change its form, and the posterior portion of the lens neither adA^ances nor recedes. 

459. Mechanism of Accommodatiox. — The lens is elastic. 
The suspensory ligament (454) keeps the lens tense and its front 



THE SPECIAL SENSES. 



263 



surface somewhat flattened. In accommodation for near objects, 
the contraction of the ciliary muscle (Fig. 101, t, t) pulls forward the 
choroid coat and the ciliary processes and slackens the suspensory 
ligament, and thus the lens is allowed to bulge forward, in virtue of 
its elasticity. When the lens is removed, as for cataract, the ability 
to accommodate is lost. Accommodation is a voluntary act. But 
few persons can effect it at will unless they are aided by visual 
sensations resulting from turning the attention to a near object. 

Fig. 102. 




Fig. 102. Diagram showing Change in Front Shape of Lens in Accommodation 
(from HehnJwltz). — L, Lens. iV, The lens adjusted for near vision. F, The lens adjusted 
for normal vision. 



The contraction of the pupil which takes place at the time of the 
accommodation results from an associated action of the central 
nervous system. The mechanism for the association of accommo- 
dation and contraction of the pupil appears to be located in the 
corpora quadrigemina (362). In looking from a distant object to 
one very near, we are conscious of an effort ; when looking from a 
very near to a distant object, there is a sense of relaxation or relief. 

Experiment. — Fix two needles upright in a yard-stick or a similar bit of wood. 
Place the needles about thirty inches apart. Hold the stick on a level with the eye, and 
in such a manner as to have the needles nearly in a line, and the nearest very close to 
the eye. Direct the attention to the far needle, then glance at the near needle : the 
former appears distinct, the latter blurred. Direct the attention to the near needle, 
then glance at the far needle : the converse is noticed. In the first instance, the image 
of the far needle is focussed on the retina, but the focus for the near needle is behind 
the retina; hence the blurred image on the retina (457). When the image of the near 
needle is focussed, the focus for the far needle is in jro)il of the retina, and diffusion 
circles are formed on the retina. 

If the near needle bo gradually brought nearer and nearer to the eye, we find that 
greater and greater effort is required to see it; the eye is rolled in, the pupil contracted, 
and the accommodation mechanism forced to its limits, till at last no eftort can make a 
clear image on the retina.. The position of the needle now nuvrks the limit of acvoimuo' 
dation for near objects. If the person bo " near-sighted," the object can bo brought yet 
nearer to the eye and still produce a clear imago. If the object be removed gradually 
from the " near-sighted" eye, a point is very soon reached at which (he image becon\os 



264 ANATO^^IY, PHYSIOLOGY, AND HYGIENE. 

blurred. This marks the limit for accommodation for the given eye for far objects. If 
the object be gradually removed away from a normal eye, the image continues clear so 
long as the object is in sight. Hence the far point for the near-sighted is near at hand ; 
for the normal eye, at an infinite distance. 

Test the eyes of the pupils by a set of SneUen''s test-types. These are a series of types 
arranged according to the size of the letters, ranging from No. I. to No. XX. No. I. is 
seen by a normal eye at a distance of one foot, at an angle of 5' ; the letters of No. II. 
are seen at two feet distance, at the same angle ; and so on, up to No. XX. The accom- 
panying test-line is No. X., and should be easily read at ten feet by the normal eye. 
Some pupils may be able to read it at eleven or more feet distant (463). 

VZBDFKKO 

460. Near Limit and Far Limit. — lu the normal [emmetropic) 
eye the near limit of accommodation is about 10 or 12 centimetres 
(3.9 to 4.7 inches) from the cornea, and the far limit, for practical 
purposes, at an infinite distance. In the " short-sighted" [myopic] 
eye the near limit is about 5 or 6 centimetres (1.9 to 2.4 inches), 
and the far limit only shortly removed from the eye. In the " flat 
eye" [hypermeti^opic] the near limit is at some distance away, and 
a far limit of accommodation does not exist. This ocular defect 
is quite common in school-children. In the "long-sighted" eye 
of old people [presbyopic] the near point is at some distance 
away, but the eye is unable to focus it, and the far point is at an 
infinite distance. In the normal eye, when no effort of accom- 

FiG. 103. 




Fig. 104. 




modation is made, the principal focus of the eye lies on the retina 
(Fig. 103) ; in the near-sighted eye, in front of it (Fig. 104) ; and 



THE SPECIAL SENSES. 265 

in the flat eye, behind it (Fig. 105). The near-sighted eye and the 
flat eye are abnormal eyes. The former condition may rise from 

Fig. 105. 




too convex a cornea, too convex anterior surface of tlie lens, spasm 
of the mechanism of accommodation, or from too great length of 
the long axis of the eyeball. The latter condition is the most 
common factor. This defect is corrected by using concave glasses. 
The flat eye possesses too short an antero -posterior axis. Its defect 
is corrected by using convex glasses. 

461. Imperfections of the Eye. — What is known as a normal 
eye is not a perfect optical instrument. SpheiHcal aberration exists 
more or less, owing to the irregularity of the refractive power of the 
lens from the centre to the circumference. This is not entirely cor- 
rected by the narrowing of the pupil. Most eyes are more or less 
astigmatic, owing to unequal curvature of the cornea. When the 
cornea is most convex in the vertical meridians, horizontal lines 
are brought to a focus sooner than are vertical lines, and vice versa. 
An astigmatic person can often see letters made up of vertical and 
oblique lines distinctly, but not, at the same time, horizontal lines. 
A slight amount of chromatic aberration has been detected. The 
lens does not appear to be constructed to obviate this defect. In the 
vitreous humor are often seen muscce volitantes, which appear as 
beads, streaks, patches, granules, etc. Occasionally radiate figures, 
corresponding to the arrangement of the fibres of the lens, appear 
in the field of vision. 

462. Visual Sensations and Perceptions. — Lio-ht 
falling on the rods and cones of the retina excites sensori/ 

462. What nrise in the retina? Whnt becomes of the impulses ? 
How does a sensation arise? • How a perception ? What portion of 
the retina is involved ? How is the field of vision interpreted ? AVliat 
of the blind spot ? Of the yellow spot ? 

M 2o 



266 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

impulses. Concerning the manner of production of the 
impulses in the retinal structures, nothing at present is 
known. These impulses pass over the fibres of the optic 
nerve to the corj^ora quadrigemina (362). From thence 
impulses reach the cerebral centres, produce changes in the 
protoplasm, and give rise to what we call a visual sensation. 
In the mind the sensations are co-ordinated into percep- 
tions. The sum of these sensations constitutes the field of 
vision. The structures in which the visual impulses arise 
lie behind the retinal blood-vessels. The image on the 
retina is inverted ; the top is bottom, the right is left, etc. 
When the field of vision is interpreted by touch, there is a 
mental re-inversion of the image-perception. At the point 
where the optic nerve enters the eye is located the blind 
spot. The region of most distinct vision is the fovea cen- 
tralis of the yellow spot. This spot lies at a spot corre- 
sponding to the axis of the eye (Fig. 101). 

463. A Visual Sensatiois^ has a duration longer than that of 
the stimulus. The sensation of a flash of light lasts much longer 
than the time occupied by the light- vibration acting on the retina. 
If tw^o flashes occur near enough together, they occasion a single 
sensation. In order to prevent fusion, the interval with the faint 
light must be more than one-tenth of a second ; with a strong light, 
more than one-thirtieth to one-fiftieth of a second. It is easier to 
distinguish differences of brightness between two faint lights, as of 
a dip and of a spermaceti candle, than between two bright electric 
lights. Most people see two stars as one when the distance between 
them subtends an angle less than 60^''. Hisschmann could distin- 
guish objects 50^^ distant fi^om each other. Snellen^ s test-types are 
constructed on the principle of having the limbs and subdivisions 
equal in breadth to one-fifth of the height. The lettei-s are of such 
a height as to be seen by a normal eye under a visual angle of 5^. 
Hence each limb of the letters is seen under a visual angle of 
60^^. Color -sensations depend on the wave-length of the rays falling 
on the retina in a given time, and on the amount of white light 
falling on the same retinal area at the given time. White light 



THE SPECIAL SENSES. 267 

dilutes the colored light sensations. The three primary retinal 
sensations correspond to what we call red, green, and violet. The 
sensation of color is more distinct in the centre of the retina than 
near the circumference. 

464. Coloh-Blindness is an incapacity on the part of the visual 
organs to respond to the stimulus which one of the three kinds of 
light is calculated to produce. White is not white to the color- 
blind. To the "red-blind" it is a mixture of green and violet; to 
the " green-blind," of red and violet. It is well known that persons 
vary in the power of distinguishing color. Some persons regard as 
similar colors which to others are distinct. The most common form 
is the inability to distinguish green and red from each other. 
" Green-blindness" and " violet-blindness" are quite rare. " Eed- 
blindness" is quite common. The "red-blind" in railroad and 
steamer service learn to distinguish red from green lights by one 
of them being bright and the other dim. Too often, on foggy nights, 
this test fails them, an accident happens, and they are discharged 
for drunkenness, carelessness, etc., when the fault was color-blind- 
ness. Hence it is of importance that all line-men and deck-officers 
should be tested as to their ability to distinguish quickly red from 
green, especially at night. Holmgren's variously-colored worsted 
test is the most satisfactory. 

465. After-Images. — If the eye is directed to the sun, the image 
of the sun is present for a long time after the eye is turned away. 
If the eye is directed for some time to a white image on a black 
background, and then turned to a white wall, a similar image in 
gray is seen on the wall. The appearance of the gray image is ex- 
plained as the result of retinal exhaustion. The steadfast gaze at 
the white object has exhausted the retinal area which ap})reciates 
white, and when the rays from the white wall strike on this ex- 
hausted area they are not a])preciated,— that is, there is a dark sen- 
sation space, — but the white rays on the adjacent areas reach ovi^r 
the exhausted areas, and a gray image is perceived. When a red 
patch is looked at and exhaustion results, the negative image is 
green; orange, blue; yellow, an indigo-blue. A bU^nding of the 
three primary colors, as seen in the sensation produced by a rapidly- 
revolving chromatic top, i)roduces a sensation of white. 

466. r>iNocuLAii Vision.— Having two eyes, we receive iVoni 
every object two setis of sensations, but under ordinary conditii)ns 



268 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

we perceive only one object. By squinting we can so influence the 
field of the retina as to render the perception double. The single- 
ness of perception depends upon the image of the object falling 
upon similar areas of the retina at the same time, and the resulting 
sensations being blended into one perception. The two eyes move 
together, upward or downward, to the right or to the left, con- 
verge for near vision, and diverge to parallelism for far vision. We 
cannot diverge the eyes beyond parallelism of the axes : hence the 
two images of any object must fall on corresponding parts of the 
retinae. The mechanism for the co-ordination of the movements 
of the eyeballs in order to secure one perception is located near the 
corpora quadrigemina (362). 

Binocular vision affords man the means of forming visual judg- 
ments concerning the form, size, and distance of objects. Single- 
eye judgments are more liable to error than binocular. One eye 
supplies that part of the visual field which is lacking in the other. 
By a long series of associations of visual sensations, those derived 
irom the movements of the eyeballs, and those derived from touch, 
we are enabled to form, by the eyes alone, judgments concerning 
objects of the external world. 



Touch. 

467. The Skin (48) contains the principal end-organs 
of the sense of touch. The mucous membrane contains 
end-organs for the sense of touch for a short distance only 
from its junction with the skin at the mouth, nostrils, etc. 
A hot or cold liquid, or a hard or soft body, in the mouth 
occasions a definite sensation ; either of them in the stom- 
ach or intestines, only a general sensation of pain. As to 
the exact nature of the end-organs in the skin there is still 
doubt. At one time the "tactile corpuscles," and at 
another the "end-bulbs of Krause," have been regarded 
as the specific organs of touch. 

467. What are found in the skin and mucous membrane ? What of 
mucous-membrane sensations? What are the end-organs of touch? 



THE SPECIAL SENSES. 269 

468. If the optic nerve is stimulated in its course, the 
brain recognizes a sensation of light ; if the auditory nerve, 
of sound ; if the gustatory nerve, of taste ; if a general 
nerve, of pain (379). If the end-organ the retina be 
stimulated by its appropriate stimulus, light, the brain 
recognizes a definite perception in its field of vision ; if 
the end-organs of the labyrinth, a definite perception of 
sound ; if the end-organs of the nerve of taste, a definite 
perception of sweet, acid, etc. ; if the end-organs of the 
skin or parts of the mucous membrane, a definite percep- 
tion of pressure or of temperature. We judge of the weight 
or the hotness or coldness of a body, because the end-organs 
in the skin enable the brain to perceive how much it presses, 
or how^ hot or cold it is when compared with the part of 
skin in contact with the same. Further than this the skin 
organs do not afford us information as to the nature of the 
body. An induction shock and the prick of a needle in 
the skin give rise to similar sensations and perceptions. 

469. Sensations of Pressure. — (1.) We can distin- 
guish the difference of pressure between one and two ounces 
as well as between ten and twenty. (2.) When two touch- 
sensations follow each other sufficiently near, they become 
fused. Thus, if the tip of the finger be placed on a slowly- 
revolving notched wheel, each notch will be felt ; if the 
speed be increased sufficiently, the sensations are fused into 
one prolonged sensation. (3.) If the hand be placed on 
the table, and w^eights be piled on the same, the increment 
of drachm-weights will scarcely be noticed, while that of 

468. Speak of general stimulation. Of special stimulation. What 
do the skin-organs recognize ? 

460. Speak of dilferenocs of pressure. Of near touch sensations. 
Of the application of weights. Of variations of pressure. 01' sen- 
sitive parts. 

23* 



270 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

pound-weights will soon become painfully evident. (4.) 
Variations of pressure are more readily distinguished when 
they follow in succession than when they occur at the same 
time. The end-organs of the palmar surfaces of the fingers 
and of the forehead are more sensitive to pressure than 
those of the sole of the foot, of the thigh, or of the fore- 
arm. 

470. Sensations of Temperature. — In judging of 
the temperatures of bodies, or of different parts of our 
own body, we start with some part, as of the hand, as a 
standard. The more gradual the change of the tempera- 
ture, the less the sensation. Plunging into and withdraw- 
ing the hand from hot water excites acuter sensations than 
keeping the hand quiet in the water. The sensations of 
slight cold are more noticeable than those of slight heat. 
The range of most accurate determination seems to lie be- 
tween 27° C. and 33° C. (80.6° F. and 91.4° F.). The 
cheeks, temples, tongue, and lips are more sensitive than 
the hand. The legs and trunk are least sensitive. 

471. Localization of Sensation. — When any part 
of the body is exposed to a notable variation of pressure 
or temperature, consciousness perceives that a particular 
part of the body has been touched or heated. We refer 
the sensation to the place of the origin of the impulse, not 
to the outer world, as in sight, hearing, smell, etc. The 
power of localizing sensations varies in different parts of 
the body and in different individuals. As a general rule, 
the more movable parts, as of the tip of the tongue, the 
lips, the tips of the fingers, etc., most readily discriminate 

470. How do we judge of temperature ? What sensations are more 
noticeable ? What parts are most sensitive ? 

471. How are sensations localized? What parts are most acute? 
How is improvement explained? What may be learned? 



THE SPECIAL SENSES. 271 

sensations. The improvement of touch through tactile 
exercise is explained by a more exact limitation of the 
areas of sensation within the brain, not by the development 
of new end-organs or nerves in the skin. By the cultiva- 
tion of this sense, guided and corrected by the other senses, 
especially that of sight, we are enabled to build up ideas 
concerning the form, the roughness or smoothness, the plane 
or round surfaces, the hardness or softness, and the hotness 
or coldness of objects. By culture the sense of touch can 
be wonderfully improved, as is shown in the delicate touch 
of the skilled mechanic and the knowledge acquired by 
the blind. 

Experiments. — With a pair of sharp-pointed dividers test the sensitiveness of the 
skin. Place tlie two limhs at siicli a distance ajiart as sliall, wlieu both are pressed simul- 
taneously, excite the sensation of two pricks. Push the limhs nearer and nearer, until 
the two points Avill excite only one sensation. Kepeat the tests for different pai'ts of the 
body. It will be found that the tip of the tongue, the palms of the last phalanx and 
of the second phalanx of the finger, are the most sensitive, and that the back, the ster- 
num, the foreai-ra, and the back of the hand are the least sensitive parts of the hiiman 
body. 

On the forearm determine the closest distance of the divider-points which will excite 
two sensations. Press a heavy ring on the part, and within the ring apply the points ; 
only one sensation will be noticed ; that is, the neighboring sensation has obscured the 
previous double sensation. At another ])art determine by Uyhl pressure the nearest dis- 
tance for two sensations. Now press heavily, and only one sensation will be recognized. 
Light pressure gives a clearer sensation than heavy pressure. 

Blindfold a person. Place a marble, or other smooth, uniform body, between the fore- 
finger and middle finger; the presence of one body will be recognized. Bend the middle 
finger over and beyond the forefinger, and then place the marble in the fork thus fi)rmed, 
so that it touches the radial side of the forefinger and ulnar side of the middle finger; 
the presence of two bodies will be recognized. This is an error of judgment, because, 
in ordinary affairs, these two portions of the skin cannot bo touched by one object at the 
same time. 

Muscular Sense. 
472. If the hand and arm be placed on the table, antl 
if different weights be })laced on the palm, a person can 
crudely estimate differences in the weight hy pressure sen- 



472. How does prossuro iiulioalo woisxli* '^ How do wo ostimato tlio 
woii;-lit of sniiill bodies? Wliat is tho nuisoiiliir S(>nso ? 



272 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

sations. If the person holds the weight or given body in 
the hand, free from the table, he not only feels pressure, 
but is aware of muscular exertion to hold and to lift the 
body. Through the nerve-connections he is made con- 
scious of this resistance. By a combination of pressure 
sensations and muscular exertion sensations, man is able to 
form quite accurate judgments of the weight of bodies. 
The muscular sense is the sense which informs us of the 
amount of the resistance to muscular action. 

473. The muscular sense is quite necessary for the proper 
guidance of all bodily movements, as of walking, as of 
prehension, as of all kinds of handiwork, etc. In all 
bodily movements consciousness is aware of the amount of 
contraction to which the muscles are put. This is well 
illustrated, when we make up judgments as to the size of 
an object, by the movements of the eyeballs, aided by 
sight. Consciousness is aware of the muscle or group of 
muscles put into action and of the amount of that action. 
It is also aware of the condition of the muscles, whether 
light and buoyant, or heavy, tired, and painful. The seat 
of the end-organs of this sense has not yet been deter- 
mined. Certain physiologists have located them in the 
terminals of the nerves in the muscles ; others, in the cen- 
tral nervous system, and affirm that the changes in the 
centres affect consciousness by giving a conception of the 
effort expended in arranging the incoming and outgoing 
impulses. 

Sense of Equilibrium. 

474. The movements of our bodies are governed and guided by 
a conscious appreciation of our body and of its relation to surround- 
ing objects and the atmosphere. This appreciation is largely made 
up of visual sensations, of muscular sense, and of touch sensations. 
When this appreciation is disturbed, as in swinging or rapidly turn- 



THE SPECIAL SENSES. 273 

ing, our equilibrium is not secure, — we become dizzy, stagger, and 
reel, are unable to co-ordinate our bodily movements or to adapt 
ourselves to the position of things about us ; yet no perversion of 
sight alone, or touch alone, or muscular sense alone, occurs. 

Experimental Kesults. — When the horizontal, membranous, semicircular canals of a 
pigeon are cut, the bird continually moves its head from side to side ; when one of the 
vertical ones, up and down. When one side only is operated upon, the trouble soon 
passes away. When both sides are operated upon, the condition persists. In the latter 
case, if the bird is calmed, the movements do not appear. If the bird is disturbed, or 
if it attempts to move, these peculiar movements are exaggerated. If the mutilated 
bird is thrown into the air, it flutters and falls in a confused manner. If balanced and 
quieted and placed at rest, it places its head in a constrained position. If it is now dis- 
turbed, its movements become irregular, and it is unable to execute combined co-ordinate 
movements. It has difficulty in getting at food which it may see, and then in picking 
up the food. If food is placed within its beak, it eats it with avidity. If the bird is 
placed in a heap of grain, guided by contact sensations, it feeds well. It can also clean 
its feathers and scratch its head, being assisted by tactile sensation from all parts of the 
body. It sees well. It appears to hear well. No paralysis has been detected in any 
group of muscles. It cannot co-ordinate its movements. It acts like a dizzy bird. In 
rabbits, section of membranous portions of the semicircular canals produces loss of co- 
ordination. 

475. The semicircular canals are placed in planes, at nearly right 
angles to one another. Hence the pressure of the endolymph (440) 
on the membranous canals in any position of the head, or variation 
of movements of the head, would be different in each of the three 
canals. If the epithelial cells and hair-like organs of the mem- 
branous canals do recognize impressions from the movements of 
the contained fluids, if the impressions are converted into impulses, 
which, transmitted over the auditory nerve, are not of an auditory 
nature, then it is possible to conceive that the impulses thus gen- 
erated in the canals by the movements of the head, becoming 
changed into sensations, may enable consciousness to judge of the 
movements which gave rise to them. Hence it is held that in the 
human semicircular canals are probably located the end-organs which 
build up the impulses concerned in the sense of equilibrium (372). 

HYGIENE. 

476. Of the Tongue.— The sense of taste (426) be- 
comes perverted by the abuse of condiments and stimii- 



470. ITow is the sense of taste injured? IIow is it iniprovod? 
What of the influence of tobacco? 



274 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



lants and the endless admixture of different articles of 
food. In children this sense is usually acute. By careful 
training the sense may become of great commercial value, 
as seen among the tea-tasters connected with the tea-houses 
of China and Japan. The use of wholesome and simple 
foods and drinks is advantageous to the sense. If not 
perverted, it often giv^es timely warning of the presence 
of injurious substances in foods and drink. The use of 
tobacco and hot-spiced foods is hurtful. 

477. Of the Nostrils. — The sense of smell (430) is 
an endowment not so much for pleasure as for protection. 
It is one of the most delicate and most available tests 
of the impurity of the air. We should not endeavor to 
blunt its pov>^ers by keeping its end-organs in an atmos- 
phere of offensive smells, either by an act of the will or 
by using a powerful and more agreeable odor, like musk, 
to mask the offensive compounds, but rather, accepting its 
warnings, remove from such offensive surroundings. The 
sense of smell is blunted by the use of snuff, by the im- 
moderate use of smelling-salts and powerful perfumes, and 
by the persistent inhaling of smoke, dust, and the odors 
arising from the decaying vegetables in the cellar, and the 
mephitic odors from the sewers and cesspools. 

478. Of the Ear. — Infants are deaf at birth ; but the 
sense of hearing (439) is soon developed. No organ con- 
tributes so much to the intellectual development of the 
child as the ear. This is well shown in the mental back- 
wardness of those of lasting congenital deafness compared 

477. What of the sense of smell ? How may it be blunted ? 

478. What of the sense of hearins;? What of its influence on the 
mental growth? Effect of cultivation? How is hearing impaired? 
What of the internal ear? How should wax be removed ? What of 
foreign bodies? Of cotton plugs? Of ear-boxing? 



THE SPECIAL SENSES. 275 

with those born blind. In youths and adults this sense 
is capable of great improvement. By its cultivation the 
blind are able to judge with considerable accuracy the 
distance of moving bodies, and the Indian to distinguish 
sounds inaudible to the untrained civilized ear. 

Hearing is often impaired by colds and resulting in- 
flammations. External and middle ear diseases may be 
excited by wetting the hair of the head and drying it 
too slowly, by clipping the hair too closely in the cold 
season, by frequent exposure of the head and neck to 
draughts of cool air, by perforation or rupture of the 
tympanic membrane, by immoderate tobacco-smoking, and 
by the extension of inflammation from the nasal pharynx 
through the Eustachian tube to the middle ear. The in- 
ternal ear is well protected from external agencies and in- 
juries by its position deep in the hardest portion of the 
temporal bone. We can do little or nothing to assist 
nature in its protection. 

In health, the wax of the canal dries, scales, and falls 
out. The hardened wax should not be dug out of the ear, 
for fear of injury to the membrana by the steel or ivory 
pins; nor should the meatus be washed with water and 
strong soap. If the wax is hardened, run in a few drops 
of warm oil or glycerin, then carefully syringe with tepid 
soft water, taking time and using sufficient water. No 
foreign body, as a bean, corn, etc., should be permitted to 
remain long in the meatus (see Chapter XY.). The intro- 
duction of a pledget of cotton into the meatus to prevent 
"catching cold" is not judicious. The pledget not only 
impairs hearing, but its presence lowers the natural powers 
of resistance against cold. The ears of children ought not 
to be boxed. The sudden compression of the air in tlie 
canal may rupture an over-fragile tympanic membrane. 



276 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

In case of ear-maladies, avoid " patent medicines," and con- 
sult the best aurist or surgeon in your vicinity. 

479. Of the Eye. Management in Infancy. — The 
number of blind persons in every community is large. In 
Massachusetts, in 1875, there was one to every five hun- 
dred and eighty-eight of the population ; in Japan, in the 
same year, one to three hundred and twenty -six. In a very 
considerable number of cases the loss of sight dates from the 
first few days or weeks of life. The majority of those who 
so early become blind bring into the Avorld good, useful 
eyes. The causes of infantile sore eyes and blindness are 
carelessness and ignorance, rather than diseases and injuries. 
The attendants of the child, from the time of its advent 
until it can care for itself, neglect proper precautions about 
light, cleanliness, and temperature. During the first few 
weeks of life the infant cannot shelter the eyes from daz- 
zling light: hence too much care cannot be taken with re- 
gard to the position of the child to light. The cleansing 
of the eyes should receive early and careful attention. The 
washing should be done with simple warm soft water and 
soft bits of clean old linen. Exposure to cold currents of 
air^ and to air fouled by the presence of soiled, damp 
clothes, by smoke, dust, and once-breathed air, often affects 
the eyes of infants injuriously. 

480. Management in Childhood. — In adults it is well 
known that there are differences in respect to the distance, 
the acuteness, and the duration of vision. Careful studies 

479. Speak of the number of blind. What is the chief cause of 
blindness? To what should attention be directed? Speak of wash-' 
ing. Mention certain injurious influences. 

480. "What has been noticed in adults ? In weak children ? What 
do the people notice ? What do they not detect ? What is noticed 
frequently in flat eye ? 



THE SPECIAL SENSES. 277 

of the eyes of children, and especially of the eyes of weak 
children, have shown that the departure from the normal 
state of the eye is early, and, in a city or town community, 
of quite frequent occurrence. Among the people, the spots 
on the cornea, cloudiness of the humors, cross-eye, etc., 
attract attention, but the commencing long eye or the 
presence of flat eye is not noticed, and thus the inability 
to perceive objects is often attributed to obstinacy and 
stupidity in the child, rather than to his inability to see 
distinctly. In flat-eyed (hypermetropic) children, squint- 
ing of the in-turned variety is of quite frequent occurrence. 
The membranes of the eyes of weak children, especially 
those living in the city, are feeble. If such children are 
induced to stay in-doors, to look at small objects, to play 
with fine dissected puzzles, to cut out small pictures, etc., 
the weak tunics of the eyes tend to be stretched backward 
during forced accommodation, and near-sightedness results 
(460). For this reason, the practice of teaching children 
to read and to write at too early an age, as at five years or 
younger, is to be condemned. The probability of harm to 
the eyes during early school-life is diminished with every 
year added to life before the child enters school or com- 
mences the continued use of his eyes on fine work. Chil- 
dren should not be compelled to fix the gaze for long 
periods on their books. In reading, and more especially 
in writing, they should not be permitted to allow the head 
to fall too far forward, as this position impedes the return- 
flow of blood from the head. With print or script of the 
usual size, the paper should never be less than ten inches 
from the normal eye. 

481. Management in the Student Period. — When a scholar 
can see well within a certain limit, but has Icv^s than normal 
vision beyond this point, mi/opia is to be suspected. A 

24 



278 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

myopic student should always wear glasses. Not only 
will his eyes then give him longer service, but he will be 
able to see more, to learn more of the world about him, 
and to know more. A short-sighted person who does 
not use proper glasses loses a large proportion of the pleas- 
ures of existence. Flat-eyed students should be early pro- 
vided with glasses. Students should not use books with 
stinted margins and printed in small and closely-compressed 
type on very poor paper. The " blackboards" now used 
in the school-room should be painted green, to avoid too 
striking contrast. The desks ought to be assigned so 
that the pupil will be enabled to have his work about 
twelve inches from the eyes, and this with little stooping. 
Students should not be compelled to read, to write, or to 
draw by an insufficient light, and more especially during 
twilight. If the position of the seats and the means of 
illumination cannot be improved, then the order of exer- 
cises ought to be changed, in order to favor the eyes. Close 
visual attention should be demanded for short periods only. 
Change of the body-position, moving from one room to 
another, five minutes' calisthenics every hour, and occa- 
sional glances out of the window, are beneficial. For the 
health of the eyes, as well as for that of the body in general, 
out-of-door sports should be encouraged. Experience shows 
that the power for sustained visual effort is markedly de- 
pendent on the general vigor of the muscular system. In 
the choice of a life-work for the young, the capabilities of 
the eye should be considered ; for eyes which would in a 
few years fail a compositor, copyist, or watchmaker would 
do good service for a gardener or a farmer. 

481. What marks the state of neai- sight ? What of the use of 
glasses ? Speak of books ; of desks ; of light ; of the change of exer- 
cises ; of position ; of sports ; of choice of life-work. 



THE SPECIAL SENSES. 279 

482. In the adult period the eyes have 'become consoli- 
dated, but yet they suffer from a variety of causes, — as 
from general weakness of the body, from deterioration of 
the blood, from determination of the blood to the brain and 
eyes, from mechanical or chemical injuries, from impure, 
vitiated, and smoky air, from uncleanliness, from excessive 
use, from the want or misuse of spectacles, from defective 
or excessive illumination, etc., etc. In all visual troubles, 
endeavor to find the cause. If possible, remove the cause 
and use appropriate agents ; if not, then mitigate the con- 
dition as much as possible by using the type-writer, writing- 
frames, suitably-tinted paper, optical devices, and appro- 
priate medication. 

483. Illumination. — Solar light is as congenial and neces- 
sary to the eye as food to the digestive organs. Pro- 
longed exclusion from sunlight, as by confinement in dark 
cells, is weakening and highly injurious. On the other 
hand, vision has been weakened or destroyed by sudden 
exposure to the dazzling light. Temporary loss of sight 
has resulted from the reflection of bright sunlight, as from 
a mirror or other polished surfitce. The eyebrows, the lids, 
and the lashes chiefly protect the eyes from excessive light 
from above; hence, for solar lighting of rooms, low win- 
dows, bright, reflecting floors, and white blinds should be 
avoided. Dazzling light, insufficient light, unsteady Hglit, 
as in a jolting railway-carriage, light with shadows, light 
falling directly into the eyes, one and all, are improper 

482. Causes of eye-troubles in atlnlts? What, can be done? 

483. Speak of sobir lio-bt. Of (loi)rivation of light. Of too bright 
light. "What should be avoided in rooni-lightino-? ]\rention im- 
proper kinds of illumination. Danger o^ twilight. Speak o^ arti- 
ficial illumination. How may the bad etleets o[' boat be mitigated? 
What of eye-work ? 



280 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

lights. Large windows and large panes of glass are de- 
sirable in all workrooms. Solar light is preferable to any 
artificial light for continued regular eye-work. Evening 
twilight is a dangerous light, for the eyes are already 
weary from the efforts of the day, the amount of illumina- 
tion is on the decrease, and the strain on the eyes becomes 
more and more intense in the endeavor to make out the 
fading characters. 

At present one of the best artificial methods of illumi- 
nation is the argand-burner student-lamp or the argand- 
burner gas table-light. The best kind of a shade is of 
white porcelain having a green outer covering. The posi- 
tion of the lamp which is most favorable for the eyes is to 
the left front of the worker, having the flame slightly above 
the level of the eyes. If the heat from the large argand- 
burner is objectionable, a flat cell, eight inches square and 
half an inch thick, its sides being formed of plate-glass 
and its cavity filled with a filtered saturated solution of 
alum, may be placed in front of the lamp, to intercept the 
heat-rays. If the eyes become dry and hot, a wet sponge 
may be placed near the lamp. If possible, all work which 
is trying to the eyes should be done under solar light. 
Reading demands greater visual effort than copying, and 
copying than ordinary writing. 

Statistics.— The report of Dr. Kisley shows that in Philadelphia, in the primarj' 
schools, there are 4.27 per cent, of myopes ; that the percentage steadily increases as the 
pupils pass to higher grades in the public school system, and that in the highest grade 
there are 19.33 per cent, of myopes. Drs. Loring and Agnew found that in New York 
City there Avere 3.5 per cent, in the youngest classes and 26.78 per cent, in the highest. 
Dr. Derby reports, as the result of the examination of four consecutive classes at Am- 
herst (Massachusetts) College : Average age at entrance, 19 ; at graduation, 23. 

At entrance. At graduation. 

Manifest hypermetropia 39 47 

Myopia , 90 120 

Emmetropia 125 87 

254 254 

34 per cent, were myopic at entrance, and 47 per cent, at graduation. Id 32 cases 



THE SPECIAL SENSES. 281 

the myopia remained stationary, and in 58 cases it increased. At St. Petersburg, tlie 
range of myopia was from 13.6 per cent, in the preparatory classes to 42.6 per cent. 
in the highest ; at Lucerne, from 0. per cent, in the children of seven years to 61.5 
per cent, in those of twenty-one years ; and at Breslau, from 0.4 per cent, in the first 
half-year students to 63.3 per cent, in the highest classes. Observations and reports show 
that in myopic eyes the percentage of other eye-diseases is greater than in noi-mal or 
hypermetropic eyes ; that myopic eyes suffering from astigmatism had the greatest ten- 
dency towards other eye-maladies; that myopic eyes are chiefly recruited from eyes 
having defects of refraction, especially hypermetropic and astigmatic ; and that the de- 
gree of myopia varies, not with each pair of eyes, but with each eye. Hence the impor- 
tance of ascertaining, at the commencement of school-life, the condition of each eye, 
the presence or absence of errors of refraction, and, if present, the degree of the de- 
parture in each eye. 

484. Myopia, or Near Sight. — The myopic person cannot see 
to the horizon or to the fixed stars ; but he can see quite clearly 
within a certain fixed limit. The belief that short-sighted eyes are 
good and strong eyes, that myopes need not use spectacles for read- 
ing or other near work if they can see to work without them, and 
that myopia improves with age, is an erroneous one. The chief 
malformation in myopia is an elongation of the eyeball. The most 
efficient cause of this elongation is the muscular tension on the 
balls during forced continued iiiturning of the eyes when engaged 
on fine work or working under poor light. If this strain be con- 
tinued, the bulging will steadily increase, and the myopia will be 
rendered "progressive" and more and more troublesome. When 
once started, and if not counteracted, it provides for its own in- 
crease. The prevention of the increase and the correction of the 
refractive defect are to be accomplished by the use of proper spec- 
tacles. The latter do not increase the sharpness of vision, but 
keep the work farther from the eyes, prevent the convergence 
strain, stop the posterior bulging, and correct the optical defects 
(460). 

485. Prevention of Eye-Diseases, — Secure pure aud clear 
air. Tobacco-smoke, smoke, aiul dust are very injurious 
to most eyes. The washing of the eyes with clear, soft 
spring-water or witli clean river-water is often beneficial. 
Hot water should be used only under the directions of a 



485. Influence of air ? Of washing? Of borax- water ? AVliat of 
weak children ? Of defects of vision ? Of frames ? Of weak sight ? 

24"!^ 



282 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

skilled surgeon. If there is a smarting, irritating, gritty 
sensation at niglit, after work, drop into each eye, before 
retiring, five drops of a solution of borax, ten grains to 
the ounce, in camphor- water. All foreign bodies should 
be promptly and carefully removed from the eye- surfaces. 
(See Chapter XV.) Weak children should not be sent 
to school until they have been brought into a state of fair 
health and strength by out-of-door pursuits. Ail defects 
of vision should be promptly treated, — the short-sighted 
organ with concaves, and the easily- fatigued, painful, dim- 
seeing, flat organ with appropriate convexes. Persons 
having such eyes should use glasses at all times. Spec- 
tacle-frames are preferable to eye-glasses, or '^ nippers," for 
constant use. The use of the single, quizzing glass is not 
advisable. Some cases of " weak sight" {asthenopia) are 
benefited by prolonged rest. In other cases, especially 
where the failure rests with the muscles, reading at fixed 
intervals for definite lengths of time is beneficial. 

486. Of the Fingers. — By common usage, the special 
organ of the higher tactile sense (469) is the hand. It is 
admirably fitted for this office by reason of the number, 
size, arrangement, and abundant nerve-supply of its pa- 
pillae. At the tips of the fingers the delicacy of touch may 
be highly developed. By education of the finger-tips the 
blind learn to read raised letters, to distinguish impressions 
on coins, and even to detect shades of color. By care the 
fingers can be given greater scope for sense-activity. The 
dry, hard skin may be made more pliable by using tar or 
oat-meal soap, applications containing glycerin, and wear- 
ing gloves at night. The fingers, if delicacy of touch is 



486. What of the seat of the sense of touch ? Speak of this sense 
in the blind. Of the nails. 



THE SPECIAL SENSES. 283 

desired, should be washed no oftener than absolutely neces- 
sary. They should never be put in hot water. By the 
use of glycerin ointment, rubber gloves, cotton flannel, and 
friction, frequent washing may be avoided. For cleansing 
the fingers, use fine soap, ammonia- water, and a brush. It 
is preferable to file rather than cut nails. The nails of 
children should be carefully attended to. The under sur- 
faces of the nails are best cleaned with a toothpick or an 
ivory cleaner. A well-formed, well-kept nail aids the tac- 
tile sense of the finger-tips, and also enhances the beauty 
of the wonderful mechanism, the hand. 



CHAPTER XIII. 

THE LAEYNX AND VOICE. 

(For dissection, see Chapter VI.) 

487. The Larynx (160) is the special organ of voice 
in man. It is a kind of hollow chamber, extending from 
near the root of the tongue to the first ring of the trachea.. 
The framework of the larynx is made up of four cartilages. 
Within this framework, extending from front to rear, are 
two thin elastic bands, covered by mucous membrane, called 
the vocal cords. 

488. Of the four cartilages composing the larynx, the thyroid is 
the largest, and consists of two lateral, quadrangular, wing-like 
plates, which meet in front and form the prominence called pomum 
Admni (Adam's apple). The cartilage is connected with the hyoid 
bone above, and with the cricoid cartilage below. 

The cricoid cartilage somewhat resembles a signet-ring. Its front 
half is narrow and convex, and its rear half broad. This cartilage 
connects above with the thyroid cartilage by an articulation which 
permits the latter to move downward and forward and the reverse. 
Below, it is attached to the first ring of the trachea by membrane. 

The arytenoid cartilages are two in number, small, triangular, and 
curved. They are placed on the summit and back part of the cri- 
coid, with which they form movable articulations. These articula- 
tions permit these cartilages to be partly revolved, to be drawn near 
the middle line, and to be elevated to a limited extent. 

489. Looking down into the larynx, two folds of its lining mem- 
brane are seen passing from the rear to the receding angle of the 
thyroid in front. These are the superior, or false vocal cords. They 

487. Speak of the larynx. Of what is it made ? What does it 
contain ? 

284 



THE LARYNX AND VOICE. 



285 



are not concerned in the production of voice. Below these folds are 
seen the true vocal cords. The latter are made up of elastic tissue 
(24), are covered by mucous membrane, and form two sharp ridges 
or projections, turned towards each other. These projections have 
very fine and smooth edges, which are placed accurately on the same 
level. Between the vocal cords is a somewhat triangular opening, 



Fig. 106. 



Fig. 107. 





Fig. 106. A Side-View of the Cartilages of the Larynx.— 1, The os hyoides (bone 
at the base of the tongue). 2, The membrane that connects the hyoid bone and thyroid 
cartilage. 3, 4, 5, The thyroid cartilage. 6, The cricoid cartilage. 7, The trachea. 

Fig. 107. A Vertical Section of the Larynx.— 2, The os hyoides. 4, The apex of 
the epiglottis. 7, The superior vocal cord. 9, The ventricle of the larynx. 10, The 
lower vocal cord. 11, The arytenoid cartilage. 12, 13, The cricoid cartilage. 14, The 
trachea. 18, The oesophagus. 



wider behind than in front, which is called the glottis. The cords 
are stretched between the recessed part of the thyroid and the an- 
terior angle of the arytenoids. The latter are acted upon by five 
pairs of muscles and the single ari/fenmdeus. The latter cau.ses the 
cords to approach each other and to become more tense. The crico- 
thyroid is the chief tensor muscle of the cords. Above the true vocal 
cords, on each side, is a cavity called the ventricle. All parts of 
the interior of the larynx are lined with mucous membrane, and, 
with the exception of that on the cords, the latter is studded with 
:mucous glands (106). 



286 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



490. Production of Sound. — Whenever a solid body 
is thrown into vibrations, provided the latter are of a cer- 
tain strength and follow one another with a certain rapidity, 
the sensation of sound is produced in the ear. If the 
vibrations are less than eight per second, or more than 
thirty-eight thousand, they produce no definite distin- 



Fia. 108. 



Fig. 100. 





Fig. 108. A View of the Larynx, showing the Vocal Ligaments. — 1, The anterior 
edge of the larynx. 4, The posterior face of the cricoid cartilage. 5, 5, The arytenoid 
cartilages. 6, 6, The vocal cords. 7, Their origin within the angle of the thyroid car- 
tilage. 9, Their termination at the base of the arytenoid cartilages. 8, 10, The glottis. 

Fig. 109. An Ideal Section of the Larynx.— 1, The trachea. 2, 2, The loM'er vocal 
cords. 3, 3, The upper vocal cords. 4, 4, Rima glottidis, or glottis. 5, 5, Cavities between 
upper and lower vocal cords, — the ventricles. 

guishable effect on the nerve of hearing. When the vibra- 
tions exceed a definite number per second, the ordinary 
ear cannot distinguish between two near sounds. The 
'pitch of a sound is determined by the number of vibra- 
tions in a given space of time ; the strength^ by the extent 
of the action of the vibrating body. In the violin, the 
vibrations of the stretched strings; in the wind instru- 



490. How does sound arise ? What of the appreciation of sound ? 
"What of pitch? Of strength? Of different instruments? 



THE LARYNX AND VOICE. 287 

ment, the successive condensations and rarefactions of the 
air in the tube ; and in the tongued instrument, the com- 
bined action of the vibrating tongue and the impulses com- 
municated by it to the air, are the sources of sound. 

491. The Seat of Voice. — Experiments on living 
animals, the result of observations after surgical operations 
on the air-passages, and the study of the larynx in action 
by means of the laryngoscope, show that the true vocal 
cords are the essential organs for the production of voice. 
In ordinary tranquil breathing, the cords are widely sepa- 
rated and the glottis has a triangular form. The glottis 
increases slightly in size during each inspiration, and con- 
tracts somewhat during expiration. During the production 
of pure vocal sounds the arytenoid cartilages are said to 
become erect, to approach and almost touch each other ; the 
posterior portion of the glottis becomes completely closed, 
and the anterior portion appears as a fine fissure, about 
one-hundredth of an inch wide, and the cords thus approxi- 
mated are seen to be thrown into vibrations. 

492. The Voice. — A current of air, driven by a more 
or less prolonged expiratory movement (175), throws into 
vibrations the vocal cords, which have been already ap- 
proximated and made of the proper tension by muscle- 
action within the larynx. The rapid movements of the 
cords impart vibrations to the column of air in the larynx, 
I)harynx, mouth, etc., above the cord, and thus give rise to 
the sound called voice. The chambers and recesses above 
the cords modify the sounds produced by the vibrations of 
the cords. Loudness depends on tlie^ strength of the ex- 

491. What are the essential origans in voice? What is the condi- 
tion of the parts durino- breathin«;- ? Diirinu; vocal sound-]n'oduction ? 

492. llow is a vocal sound produced? What modify the sounds? 
What of the muscular infiuonces? 



288 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

piratory current ; 'pitoh, on the length and tension of the 
vibrating cord ; and quality, chiefly on the physical nature 
of the cords. Intrinsic (to the larynx) muscular action 
produces variations in the tension of the cords, determines 
the length of the cord which may vibrate, and the width 
of the glottis, all the changes working together to produce 
differences in the vocal sounds. 

493. The length of the cords is constant, or varies only with age. 
The length determines the range only, and not the note given out 
at any time. The shrill voice of the child is determined by the 
shortness of the cords in infancy. In the male, at the age of puberty 
a rapid development of the larynx takes place, with an elongation 
and thickening of the cords, leading to a change in the range of the 
voice. The voices of the soprano, tenor, and barytone depend on 
the respective lengths of the vocal cords. The tension of the cords 
is variable. The chief tensor muscle is the crico -thyroid. It has 
a nerve-supply distinct and separate from the other muscles of the 
larynx, and is the most important muscle concerned in the produc- 
tion of voice. When its special nerve is cut on one side, it becomes 
impossible to produce high notes. 

494. Muscular Co-ordination. — Almost every move- 
ment, within or without the larynx, concerned in the pro- 
duction of voice, is effected by two or more muscles working 
in concert. The controlling centre of these movements is 
seated in the gray substance at the base of the fourth 
ventricle of the brain (Fig. 81, 26). If this portion be 
compressed, as in certain forms of apoplexy, or injured, 
vocalization is impeded or suppressed, though the laryn- 
geal apparatus remains in a perfect condition. Singers 
need not only flexible cords, strong respiratory and laryn- 
geal muscles, and a ringing resonance of the air-passages, 

494. Speak of co-ordination in voice. How effected? What do 
singers need ? What of the influence of external sounds ? What of 
mutes ? 



THE LARYNX AND VOICE. 289 

but a well-cultured nerve-centre. In the culture of this 
centre it is found that the impulses acting from the centres 
of hearing on to the vocal centre are of prime importance 
in the accurate management of the voice (394). Deficiency 
in this respect is commonly expressed in the phrase, such and 
such a person '^ has no ear." The muteness of tlie totally 
deaf is seldom due to defects in the laryngeal apparatus, but 
to their inability to recognize sound-waves and thus to re- 
ceive impulses from the centres of hearing. By the patient 
imitation of the facial expression they arc taught to speak. 

495. Speech, or the utterance of articulate sounds, is a 
distinctive characteristic of man. Animals have voice; 
man alone has speech. The raven may be taught to speak 
by rote, but man alone attaches meaning to the word-sounds 
and phrase-sounds he employs. Speech is a modification 
of the vibrations generated in the larynx in their outward 
passage through the cavities of the mouth and nose. The 
nerve-centres which control the power of speech, acting 
through or upon the centres of voice, appear to be seated 
on the left side of the brain, in the hind part of the third 
frontal convolution (358). The faculty of speech is natural, 
but its exercise is an art. Pressure or injur}^ to this part 
of the brain does not necessarily stop vocalization, does not 
prevent the expression of thought by writing or by signs, 
but does prevent articulate speech. 

496. Articulate Sounds are divided into vowels and 
consonants. The true voivels, or oj)en sounds, are generated 
in the larynx. They are uninterrupted vocal tones, modified 
in the outward passage by alterations in the length and 

495. Whut distinctive chanicteristic of man? What is speech? 
What of tlio centre controllin<;- voice? AVliat is its intluence? 

49G. Speak of vowels and (heir production. Of tlie nasal tone. Of 
the production of consonants. 

t N 25 



290 ANATOMY, 

shape of the pharynx, mouth, and lips. When the back 
entrance to the nostrils is not closed, the tones acquire a 
7iasal quality. The consonants are entirely formed in the 
parts above the vocal cords. They are produced by the 
expiratory current of air being in various ways interrupted 
or modified in its course through the throat and mouth. 

497. Whispering is speech without the employment of 
the vocal cords, and is effected principally by the tongue, 
teeth, and lips modifying the expiratory current. Sighing 
is produced by the parts seated above the cords. If the 
vocal cords are brought into action, the sigh is changed 
into a groan. Lisping^ stammering^ and stuttering are due 
to errors in the action of the organs of speech. Stammering 
is almost always caused by irregular action of the nerve- 
centres. 

HYGIENE. 

498. Recitations and reading aloud are useful and in- 
vigorating muscular exercises. They call into varied action 
most of the muscles of the trunk. The movements of 
the thorax in full inhalation and graduated expiration act 
beneficially in enlarging the capacity of the lungs; and the 
movements of the diaphragm and the abdominal muscles 
communicate to the digestive apparatus a healthy and in- 
vigorating stimulus. If the voice be raised, and the vocal- 
ization made as rapid as possible, the muscular effort be- 
comes great, and even exhausting. Vocal exercise should 
not be carried to the point of exciting soreness or fatigue, 
either in the thoracic organs or in the larynx. Until the 
lung-capacity and the laryngeal capabilities are drilled into 

497. Speak of whispering. Of sighing. Of groaning. Of stam- 
mering. 

498. What is the influence of reading aloud? Of sustained rapid 
vocal work? Speak of vocal drill. Of posture. 



THE LARYNX AND VOICE. 



291 



accord, the periods devoted to the exercises should be brief, 
and the intervals for rest of such a length as fully to rest 
all the parts (529). The drill of the organs, in order to 
produce purer and higher tones, should be gradual and 



Fig. 110. 



Fig. 111. 





Fig. 110. An improper position, but one not unfrequently seen in sonio of our ooniniun 
schools and in some of onr pnblic speakers. 

Fig. 111. The proi)er position for reading, speaking, and singing. 

progressive ; otherwise the laryngeal apparatus may be seri- 
ously impaired. During vocal exercise the erect posture 
should be maintained. 

499. About the fourteenth or fifteenth year the voice 
becomes irregular and harsh, the high notes are not well 



292 AXATOMY, PHYSIOLOGY, AND HYGIENE. 

sounded, and the grave tones make their appearance. At 
this time the voice of the boy changes to that of the man, 
and that of the girl becomes fixed in that of the woman. 
During this transition period, exercise of the voice in sing- 
ing ought to be moderated, or entirely suspended, in order 
to prevent laryngeal affections. 

Gymnastics and calisthenic exercises are invaluable aids 
in the culture and development of the voice, and should 
be sedulously practised when opportunity renders them 
accessible. But even a slight degree of physical exercise, 
in any form adapted to the expansion of the chest and to 
the freedom and force of the circulation, will serve to im- 
part energy to the muscular apparatus of the voice, and 
clearness to its sounds. 



CHAPTER XIV. 

THE MOTOK APPAKATUS AND LOCOMOTION. 

Directions for Dissection. 

Secure the limb of a dog, pig, rat, or other mammal, Eemove the skin. Observe the 
areolar connectice tissue and the fat contained in the meshes. Remove all loose portions 
and fragments until the glistening, bluish-white fascia, whicli binds the muscles in place, 
is cleaned. Make an incision parallel to the axis of the limb through the fascia. Eaise 
the fascia, and peel it off. Select a long, slender muscle. Carefully remove from it all 
connective tissue, taking care not to nick the muscular fibre. Separate it from the adja- 
cent muscles by cutting out the intervening areolar tissue or fat. Trace and free it to its 
upper place of attachment, the origin ; then downward, until it ends in the hard, firm 
cord, or band, the tendon. Trace the tendon by slitting up the fascia, which holds it in a 
smooth, lined groove, to its attachment in the part which is moved by its contraction. 
This point of attachment is called its insertion. 

Note the thin membrane surrounding the muscle, the parallel component bundles 
of fibres, the little blood-vessels entering the bundles, and the disappearance of the red, 
elastic fibres in the white, non-elastic tendon. Observe the movements which the short- 
ening of the muscle causes. Seek and dissect out the antagonist muscle or imiscles. 

The joint. Remove all muscle, fat, and connective tissue from about the joint. Ob- 
serve the lateral, anterior, and posterior ligaments, if it is a " hinge-like joint." Saw the 
bone off about two inches below the joint. Then saw through the middle of this bone, 
the joint, and the upper bone, laying open the parts, as in Fig. 113. Note the investing 
membrane, the periosteum ; the comimct bone ; the cancellated or open-work bone, near 
the joint; the soft, red, oily marrow; the enlargement and processes for muscular and 
ligamentous attachment, near the joint ; the cartilage tipping the bone ; the lateral firm, 
white, band-like ligaments; the white, viscid synovial Jlnid ; and, perhaps, an internal 
round ligament, movable cartilage, and a mass of fat. Cut the lateral ligaments. Observe 
tlie smooth, moist surface, the internal layer of si/norial niend)rane. Shave off a bit of 
bluish-white, translucent cartilage and compare it with a bit of bone. 

Open another joint. Note that all joints, functions and position consiiU-nd, are con- 
structed equally well; that each joint is mechanically perfect; and that tlie animal ma- 
chine is the only self-oil(>r which maniifactures its own lubricants. 

Take a long bone, as a sheep's rib, and put it in a vessel containing one part of muri- 
atic acid and seven parts of water. Allow it to remain a few days. The earthy matter 
will be mostly dissolved out. The bone will now be fiexible, and may be knotted. Place 
another bone in the fire. The animal matter is expelled, and the brittle " bono-earth" 
alone is left. 

25* 2oa 



294 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

THE MOTOR ORGANS. 

500. The parts of the human body concerned in loco- 
motion consist of the bones, joints, ligaments, and tendons 
(passive in function), and the muscles and nerve-centres 
(active in function). 



Fig. 112. 



Fig. 113. 





Fig. 112 {Leidy). Longitudinal Section of the Proximal Extremity of the Femur, 
exhibiting the arrangement of the spongy substance.— 1, 2, Positions in which the com- 
pact substance appears to resolve itself into a series of arches. 

Fig. 113. A Vertical Section of the Knee-Joint.— 1, The femur. 3, The patella. 
5, The tibia. 2, 4, Ligaments of the patella. 6, Sj'novial bursa. 12, The cartilage of 
the femur. * * *, The synovial membrane. 

501. The Bones (16) are hard, soraewliat elastic, and 
resistant. The compact bone is found in the shafts of 
the long bones (femur, tibia, humerus, etc.), and in other 
parts where strength is wanted. The cancellated structure 



500. What parts are concerned in the production of motion ? 

501. Describe bone. Speak of compact bone. Of cancellated bone. 
Of the hoUowness of bones. How are bones nourished? What is 
the periosteum? 



THE MOTOR APPARATUS AND LOCOMOTION. 



295 



is foiiud at the ends of the long bones, in order to expand 
their surface at the points of junction and to serve better 
for the attachment of muscles. The hoUowness of the long 

Fig. 114. 




Fig. 114 {Leichj). Cartilage, section throiigli tlie thickness of the oval cartilage of the 
nose.— 1, Towards tlie exterior. 2, Towards the interior surface. Highly magnified. It 
exliihits groups of cartilage cells embedded in a homogeneous matrix. 

bones endows them with greater comparative strength than 
if the same weight of bony tissue had been used in the 
solid form. In certain bones (frontal, sphenoid) the hol- 
lows contain air ; in others, marrow. The bony tissue is 

Fig. 115. 




Fig. 115 (Leidi/). Section ov Fiiuio-CAiiTii.AtiK kuom tiik Aikici.k of the Ear. The 

cells are seen cml)eddod in a fibrous matrix. 1. Exterior surfao(>, where the cells are 
parallel to it. 2, Towards tlio middle. Higlily magniHed. 

endowed with great innate strength and elasticity. This 
tissue is very vascular. Most of the blood enters bv the 
vessels of the periosteum (KJ). In (ho long bones there is 
usually an artery in the medulla. 



296 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

502. Dry Bone consists of 33 per cent, of animal 
matter, 51 per cent, of calcium phosphate (bone-earth), 11 
per cent, of calcium carbonate (chalk), and the rest of cal- 
cium fluoride, sodium chloride, and magnesium phosphate. 

Fig. 116. 




Tig. 116 {Leidy). Transverse Section of Bone from the Shaft of the Femtjb; 
highly magnified.— The large circular orifices are transverse sections of the Haversian 
canals, surrounded by concentric layers of osseous substance. Between the latter are 
seen the lenticular excavations, or lacunse, intei'comniunicating by means of canaJindi. 

503. Cartilage, under the microscope, presents a clear, slightly 
granular matrix, with nucleated corpuscles embedded in the same. 
The corpuscles are of a rounded form, or have flattened sides and 
rounded angles. Cartilage has no blood-vessels, but the matrix is 
permeated by nourishment coming from the vessels in the vicinity. 

502. Of what is dry bone composed ? 



THE MOTOR APPARATUS AND LOCOMOTION. 297 

504. Bone-Formation. — Bone is formed from cartilage or from 
fibrous tissue. In the former case the change begins in the centre 
of the cartilage-mass. A certain part of the cartilage-matrix is 
absorbed, in order to form channels into which blood-vessels pene- 
trate. Granules of lime salts are deposited from these blood-vessels 
on the walls of the channels and within the cartilage-corpuscles. 
The first deposit is usually dense and irregular in formation. If 
the channelled space increases, cancellated tissue is the result ; if 
it becomes more filled with bone-salts, deposited in concentric 
layers gradually closing around the blood-vessels, compact bone is 

Fig. 117. Fig. 118. 





Fig. 117 (Leidy). An Osseous Lacuna, exhibiting its numerous diverging canaliculi. 
Highly magnified. 
Fig. 118 {Lessing). Haversian Canal, lacunae and connecting canaliculi. 

produced. During life there is a continual deposition and re- 
absorption of bone. In the formation from Jibrous tissue the bone- 
salts are directly deposited. 

505. Microscopic Characters of Bone.— The matrix of bone 
is impermeable to fluids, and hence bone contains nutrient canals. 
Compact bone is traversed by blood-vessels, which enter by the 
Haversian canals, which channels, for the most part, run length- 
wise of the bone. The bone-tissue is arranged in concentric lami/ur, 
or plates, around the Haversian canals. In transvei-se section of 
these canals, circles of lacuna' are soon surrounding the canals. 
The lacuna3 are hollows in the lamina\. having exceedingly fine, 
ramifying tubes running in various directions, called canaliculi. 



298 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



These little tubes inosculate Tsith those of the adjacent lacunae, al- 
lowing fluids to pass from one lacuna to another. Within the lacunae 
are found nucleated masses, the bone-corpuscles, which are charac- 
terized by a multitude of fine processes occupying the canaliculi. 
An arrangement of bone-laminae, containing lacunae and canaliculi, 
around a central tube is called an Haversian system. The whole 
compact tissue of bone is an aggregation of such systems, the inter- 
stices being filled with fragments of similar laminae. 



Fig. 119. 



Fig. 120. 





Fig. 119.— 1, 1, Coronal suture. 2, Sagittal suture on the top of the skull. 3, 3, Lamb- 
doldal suture. 

Fig. 120. — 2, 3, The ligaments that extend from the clavicle (1) to the scapula (4). The 
ligaments 5, 6, extend from the scapula to the first bone of the arm. 

506. A Joint, or Articulation, is a junction of two 
or more bones. Joints permit the movements of the ani- 
mal frame ; they serve to deaden internal shock, produced 
by the contact of the body with external objects, and they 
contribute to the strength of the skeleton, especially of the 
back and the lower limbs, for a pillar of a given height 
and thickness has less power to resist vertical pressure than 



506. What is a joint? What are the functions of joints 
Examples ? 



Kinds? 



THE MOTOR APPARATUS AND LOCOMOTION. 299 

a number of shorter pillars built up one above the other 
to an equal height. Joints are of two kinds, — immovable, 
as of the frontal and parietal bones, or of the vomer with 
the azygos process ; and movable, as of the hip, shoulder, 
and ankle. 

507. In a Movable Joint the bones are merely in 
contact with each other. The ends of the bones are usu- 

FiG. 122. 





Fig. 121. Diagram of a Joint.— 1, 1, Extremities of bones. 2, 2, Terminal cartilages. 
3, 3, 3, 3, The dotted line which indicates the ontlines of the closed synovial sac. 

Fig. 122. A Lumbar Vertebra. — 1, The carlilaginons substance that connects the 
bodies of the vertebrae. 2, The body of the vertebra. 3, The spinous process. 4, 4, The 
transverse processes. 5, 5, The articulating processes, fi, 6, A portion of the bony bridge 
or arch that assists in forming the spinal canal (7). 

ally expanded (Fig. 114). The end of one bone is com- 
monly convex, and that of its companion bone concave. 
The ends of the bone are covered by a thin layer of bluish- 
white, elastic Cartilage (503). This cartilage is closely 
adherent, and its free surface is highly polished. It serves 
to deaden shock and to facilitate motion. 

508. The Synovial MEi\rBRANE is a thin, delicate web, 
arranged in the form of a short, wide tube. The ends of 



507. Describe a movablo joint. AViiat is car(il:ii;-o ? "What does 
it do? 

508. What is the synovia ? Ooscribo the seorotini;' nioiubrano. 
What is the use of synovia ? 



300 



ANATOMY, PHYSIOLOGY, AND HYGIENEI* 



the tube are attached to the margins of the articular sur- 
faces of the bones; the outer surface is connected with the 
inner surface of the ligaments, and the inner, cell-covered 
surface secretes a fluid, called synovia (Fig. 113). The 
synovia is whitish, viscid, and glairy, and is much like the 
white of an Qgg. It serves to lubricate the surfaces of the 



Fig. 123. 



Fig. 124. 





Fig. 123 (Leidi/). The Right Knee-Joint, laid open from the front. — 1, Articular sur- 
face of the femur. 2, 3, Crucial ligaments. 4, Insertion of one of these ligaments into 
the tibia. 6, 7, Internal and external semilunar fihro-cartilages. 8, Ligament of the 
patella turned down, so as to exhibit the synovial bursa (9) beneath. 10, Superior tibio- 
fibular articulation. 11, Interosseous membrane. 

Fig. 124 {Leldy). Front View of the Right Knee-Joint.— 1, Tendon of the quadri 
ceps extensor muscle. 2, Patella. 3, Ligament of the patella, or tendinous insertion of 
the muscle just mentioned. 4, 4, Capsular ligament. 5, 6, Internal and external lateral 
ligaments. 7, Superior tibio-fibular articulation. 



cartilages (507), and thus prevents grating, lessens friction, 
and minimizes the wear. Its function is similar to that of 
the oil used on the bearings of machinery. BuRS^ con- 
sist of an areolar tissue sac containing a viscid fluid. They 
are found interposed between surfaces which move upon 
each other, as of the gliding of a tendon (Fig. 113, 6) or 
of the skin over projecting bone-surfaces. A bunion is an 



THE MOTOR APPARATUS* AND LOCOMOTION. 301 

enlarged and inflamed bursa at the inside of the ball of 
the great toe. 

509. Ligaments. — Outside of the synovial membrane 
are to be seen the proper ties between the bones, called 
ligaments. They are composed of white fibrous connective 
tissue (Fig. 6). In certain parts they are broadly expanded, 
like membranes (Fig. 120, 5), as in the shoulder capsular 

Fig. 125. 




Fig. 125. A Side-View of the Bones of the Foot, showing its Arched Form. The 
arch rests upon the heel behind, and the hall of the toes in front.— 1, The lower part of 
the tibia. 2, 3, 4, 6, Bones of the tarsus. 6, The metatarsal bone. 7, 8, The bones of the 
great toe. 

ligament. In other parts they form bands of various shapes, 
as in and about the knee-joint. They tie the bones very 
firmly, yet permit much motion. In certain joints they are 
so arranged as to permit free motion in certain directions 
but limit it in others. 

510. Movable Joints are of three varieties, — planiform, hinge- 
like, and ball-and-socket. The planiform have more or less plane 
surfaces and gliding movements, as in the tarsal and metatarsal ar- 
ticulations of the foot. 8uch joints allow limited motion, deaden 
shock, impart elasticity and slight flexibility. The hingc-Iikc jnn-mit 
motion in two directions in one plane, as in the elbow, ankle, and 

509. What arc ligaments? Spoak of their forms. Of their func- 
tion. 

26 



302 ANATOMY, PHYSIOLOGY, AND HYGIEXE. 

fingers. The ligaments on the sides of such joints are very strong, 
the other ligaments varying in size according to position. In the 
case of the fingers and of the ankle-joint, the tendons of certain 
muscles replace the ligaments. In the ball-and-socket joint there is 
a cup-like cavity lined with cartilage in the one bone, and a corre- 
sponding head-like extremity on the other, the bone being held in 
place by a membranous capsule. This kind of joint permits motion 
in all directions, as in the hip- and shoulder-joints. 

511. IxTERAETicuLAR CARTILAGE. — 111 Certain joiiits, 
plates of fibro- cartilage are found between the articulating 
surfaces, as between the lower jaw and the temporal bone, 
the clavicle and the sternum, and within the knee-joint (Fig. 
123, 6, 7). They make the joint deeper, allow more free- 
dom of motion, and tend to prevent dislocations. Cushions 
of fat are found in the knee- and hip-joints. Between the 
vertebrae are introduced thick cushions of elastic fibro-car- 
tilage (Fig. 75). 

512. TABLE OF THE PRINCIPAL SKELETAL MUSCLES. 

(See Figs. 126, 127.) 
The Head. 
OccipUo-frontalis, moves the scalp. 
Orhicularis palpehrarum, closes the ej'e. 
Orbicularis oris, closes the lips. 
31usseter, jg^g^.j^^e the lower jaw. 
Temporal, > 
Digastric, depresses the lower jaw. 

The Neck. 

Stenio-cleido-mastoid, moves the head forward or to one side. 
Trapezius (7), moves the head and neck backward. 

The Teink (anterior). 
Diaphragm, muscle of respiration. 
Pecloralis riinjor, moves the humerus and scapula. 
Sen-ahis wugmis, aids in violent respiration. 
hdercoslah, muscles of respiration. 
Beclns abdominis, | ^^^^ ^y^^ ^^^^^ forward. 
Psoas magnnx, ' 

Obliquus externns (26), ) assists in violent expiration. 
Obliqiais interims, J bends the body forward. 



511. What are interarticular cartilages? Their function? "What 
of fat "^ Of vertehral cartilas^es? 



THE MOTOR APPARATUS AND LOCOMOTION. 303 

Fig. 126. 




304 ANATOMY, PHYSIOLOGY, AND HYGIENE, 



The Trunk (posterior). 

Ehomboideus major A ^^^^ ^^^ ^^^^^j^ backward. 

Rhomboideus minor, ) 

Latissimus dorsi (24), moves the humerus downward and backward. 

Serratus posticus inferior, muscle of expiration. 

The Upper Extremity. 
Deltoid (8), elevates the arm. 
Subscapidims, 

Sup7-a-spinu(as, y rotate the humerus. 

In/ru-s 



'scupuuu-is, \ 

ra-spinutas, > rotate th 

ru-spii,alns (12), i 

Bradiiulif^ loiticut^,} a ^.i r 

' > flex the forearm. 
Biceps, J 

^'■'^^^^(^")'} extend the forearm. 
Anconeus, J 

Flexor carpi ulnaris and radialis, move the carpus. 

Flexor digitonmi, flex the fingers. 

Extensor carpi radialis and tdnaris (21), antagonize the flexors. 

Extensor dujitoriim (22), antagonize the flexors. 

(Upward of thirty muscles act on the fingers.) 

The Lower Extremity. 

Glutseusmuximus {1^),\ , , , ^ ■,,.-, 

( keep the body erect, rotate the thigh, move the thigh back- 
GltUseus ntedius, r 

„, , . . ward. 

Glutsms minimus, -' 

Psoas magnus, '] 

Pectmeus, ^^^^^ ^^^^ thigh. When the limbs are fixed, bend the body forward. 

Iliacus. 



J 



Adductor longu 

Rectus fern or is, -\ 

^ry^j. (^extend the leg. Their common tendons {Quadriceps fe- 

-.J , . „„i . , I wojv's) contain the patella. 

Vaslvus externns and interyns,-' ' ^ 

Sai-torit(s (tailor's muscle), flexes the leg on the thigh. 

Biceps femoris, -v 

Semi-tendinosus (30), ^^flex the leg. 

Semi-membi-anosus, •' 



yus, 

'ick 



move the thigh inward, 
flex the foot. 



Gracilis, 
Abductors, 
Tibialis anticus, 
Proprius pollick, 

Gastrocnemius (32;, j. acting through the tendo Achilli'^, extend the foot. 
Soleus, 

Extensor diqitorum, 1 „„„„ ,-, „ , ^ 

■' ' V move the toes. 

Flexor digitorum, J 

(Upward of twenty muscles act on the toes. 



THE MOTOR APPARATUS AND LOCOMOTION. 305 

Fig. 127. 




306 ANATOMY, PHYSIOLOGY, AND HYGIENE. 




513. Tendons of Muscles. — The skeletal muscles are, 
for the most part, arranged to act on the bones as on levers. 

In most cases they are 
Fig. 128. attached at both ends to 

the bones, in some places 
directly^ as in the inter- 
costals, at other places 
indirectly J as in the tendo 
Achillis(Fig.l26). Ten- 
dons are the white, flexi- 
ble, strong, and non- 
elastic cords, or bands, 
in which the muscular 
fibres terminate (Fig. 11). 
The tendon by which a 
muscle arises {origin) en- 
ables a large number of 
bulky, muscular fibres to 
act from a definite point of the skeleton, whilst the tendon 
of attachment (insertion) transmits the muscular force to 
some other equally precise point of bone (Fig. 130, 4, 5). 
The tendons reflect the muscular force over the joints and 
other parts of the skeleton, as well as through loops (Fig. 
128, 4); they economize muscular tissue, and they afford 
lightness and elegance, as is seen in the ankle and wrist. 

514. Action of Muscle (18, 19, 75, 76).— When the 
skeletal muscles swell and shorten their fibres, the part 



Fig. 128. PuLtKY Arranukmknt of a Mus- 
CLK. — 1, Digastric muscle attached to the mas- 
toid process of the temporal bone behind the 
ear. 2, Its attachment to the lower jaw. .3, 
Hyoid bone. 4, The pulley arrangement of the 
digastric and stylo-hyoid muscles. 



513, What do the skeletal muscles do? How attached? What are 
tendons? What of the use of tendons of origin? Of tendons of 
insertion ? What advantage results ? 

514. What results from muscular contraction ? What differences 
in action ? Give examples of the three orders. What of the third 
order ? What of flexors ? Of extensors ? 



THE MOTOR APPARATUS AND LOCOMOTION. 307 

into which they are inserted is moved. If both ends of 
the muscle are attached to soft parts, constriction usually 
results ; if one end is attached to bone and the other to a 
soft part, the latter is moved ; if both ends are attached to 
bone, the one offering the least resistance is moved, and the 
action is after the manner of levers : thus, the contraction 
of the muscle of the neck causes the head to move on the 
occipital condyles as fulcrums, and the heavy face is ele- 



FiG, r29. 




Fig. 129 {Leidy). Metacarpal and Phalangeal Bones of the Fingers, with their 
Tendons and Ligaments.— 1, Metacarpal bone. 2, Tendon of the superficial flexor. 
3, Tendon of the deep flexor, passing through a perforation (*) of the superficial flexor. 

vated (lever of the first order) ; the toes resting on the 
ground, the fulcrum, the contraction of the muscles of the 
calf raises the body on the toes (lever of the second order) ; 
the contraction of the biceps and brachialis of the arm 
(Fig. 130) causes the forearm and hand quickly to approach 
the arm (lever of the third order). The latter order occurs 
most commonly in animal mechanics. Under this order, 
with a slight shortening of the muscle, great motion of the 
part, with rapidity and precision of movement, is secured, 
though with the expenditure of much force. In general, 
the flexors (like tlie biceps of the arm or of the leg) act at 
greater mechanical advantage than the extensors, like the 
quadriceps of the leg. In the extensors the power acts 
at all times obliquely, therefore they are larger and more 
bulky than the flexors. 

515. Co-ordinate Movements of the Body. — In 
most movements several muscles act together in concert. 



I i 



308 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

After contraction has ceased, gravity or elastic reaction in 
certain cases causes the parts to return to a state of equilib- 
rium. In other cases, a set of antagonistie muscles are 
brought into action. Experience shows that the proper 
movements of the body depend more upon the proper co- 
operation of the muscles than upon the force of the contrac- 

FiQ. 130. 




2 4 

Fig. 130. Diagram or the Third Order of Lever. — 1, The bone of the arm above 
the elbow. 2, One of the bones below the elbow. 3, The muscle that bends the elbow. 
This muscle is united, by a tendon, to the bone below the elbow (4) ; at the other ex- 
tremity, to the bone above the elbow (5). 6, The muscle that extends the elbow. 7, Its 
attachment to the point of the elbow. 8, A weight in the hand to be rained. The 
central part of the muscle 3 contracts, and its two ends are brought nearer together. 
The bones below the elbow are brought to the lines shown by 9, 10, 11. The weight is 
raised in the direction of the curved line. When the muscle 6 contracts, the muscle 3 
relaxes and the forearm is extended. 

tions. The skilled blacksmith does a given job more quickly 
and with less fatigue than the unskilled, because he uses 
his powers to greater advantage. Experiments show that 
nearly all movements of the muscles are co-ordinate (593). 
In order to execute a composite motion, like a leap, the 
muscles must begin to work in the proper order, and the 

515. How is equilibrium re-established ? What does experience 
show? "What of the composite movements in a leap? What of 
the mechanism ? 



THE MOTOR APPARATUS AND LOCOMOTION. 309 

energy of each muscle must increase, halt, and diminish, 
according to a proper order, so that the result shall be the 
correct position of the limbs, the just balance of the body, 
and the proper velocity of the centre of gravity in the right 
direction. The peculiar mechanism of the composite co- 
ordinate movements resides in the motor ganglion cells 
of the central nervous system (372). As yet, little is known 
of the process by which the human animal imparts a defi- 
nite duration to the energy of the muscles. 

516. Sensory Influence. — The motor ganglia are 
constantly receiving information from the sensitive surfaces 
of the body. The impulses arising from external influ- 
ences are constantly being sent inward to the sensory gan- 
glia, from which they are reflected upon the motor gan- 
glia, and may thus inhibit, accelerate, or modify the ac- 
tivity of the latter. The nerve-impulses from the mental 
centres, the optic centres, and the centres of sense of 
equilibrium (474) and of muscular pressure (370) appear 
to exert an influence on the motor ganglia, causing the 
latter to keep the muscles in a proper state of adjustment 
for the duty at hand, or to lose control of them. 

Alcoholics taken regularly in excess (338a) interfere mark- 
edly with all fine combined movements, such as surgical 
operations, delicate mechanical manipulations, billiard-play- 
ing, etc. Whetlicr this is due to its direct action on the 
muscle elements, to influence on the centres (87rt), or to inter- 
ference with the conductive power of nerve is not settled. 

517. The Erect Posture, in which the weight of the body is 
borne by the phuitar arches (Fig. 126), is the result of co-ordinate 
contractions of the muscles of the trunk and legs. The object of 
these contractions is to hold the body in such a position as to keep 

51G. How do external conditions influoneo tho motor gangliii ? 
"What is the influence of the other centres ? 



310 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



the line of gravity within the area of the feet. A dead body will 
not remain standing when unsupj^orted ; the unconscious unsup- 
ported man falls ; the growing child does not acquire the ability to 
stand erect until after months of constant practice, accompanied by 
numberless falls. Experience shows that the education of the co- 



Fig. 131. 



Fig. 132. 




Fig. 131. Erect Position of the Body. — 1, A perpendicular line from the centre of the 
feet to the upper point of the spinal column, where the head rests. 2, 2, 2, Spinal column 
with its three natural curves. Tlie head and body are so balanced that the muscles are 
not kept in a state of tension. 

Fig. 132. Stooping Position of the Body. — 1, A perpendicular line. 2, Unnatural 
curved spinal column, and its relative position to the perpendicular line (1). The curved 
position of the body and lower limbs keeps the muscles in tension, which exhausts their 
energy. 

ordinating motor ganglion cells in men is slow and tedious, and 
that in some cases (chorea) these centres are almost incapable of 
education. 



THE MOTOR APPARATUS AND LOCOMOTION. 311 

In walking, there is a moment in which the body rests vertically 
on the foot of one leg, while the other is inclined back, with its 
heel raised and its toes resting on the ground. In motion, the 
weight of the body is transferred from one limb to the other alter- 
nately. Before the limb. which is raised and advanced reaches the 
ground, the body is propelled forward by the straightening of the 
ankle of the foot which is behind. 

In running, the heel is not brought to the ground ; in walking, 
it is. In walking, the whole propulsive action is from the foot ; in 
running, the knee and hip, being both greatly bent, give vast addi- 
tional impulse. There is a space of time when neither foot of the 
runner is on the ground. 

In leaping, all the joints of the lower limbs are flexed in prepa- 
ration, and the impulse given by their sudden extension propels 
the body through the air. In leaping, the limbs are extended to- 
gether; in running, they are extended alternately. 

518. Effect of Muscular Exercise. — The lung-ac- 
tion is greatly hurried. The blood -flow is enhanced. The 
quantity of air inspired and of carbonic acid exj)ired is 
wonderfully increased. The action of the heart rapidly 
increases in force and frequency, and the flow of blood 
through all parts of the body is augmented. The blood has 
been found to flow more freely and of richer quality through 
the vessels of the working muscle than through those of 
the quiescent muscle. The sJcin becomes red from the ful- 
ness of the vessels, and the perspiration is much increased. 
The increase of carbon excreted demands an increase of 
carbon to be given in the form of food, and hence the 
appetite is largely increased. The demand for meat and 
fats, rather than for carbo-hydrates, is noticed. Tlie diges- 
tion improves, and the absorption becomes more perfect. 

518. What is the effect of musouhir exercise on the lungs ? The 
heart? The skin? The appetite? Tlic bruin? The skolotal nius- 
clos? What niicroscopic changes? 



312 ANATOMY 

A sufficiency of exercise makes the performance of mental 
work more perfect, renders the action of the nerve-ganglia 
quicker, readier, and more exact, and strengthens the ability 
to cope with mental obstacles. Under continued exercise 
tlie smooth muscles appear to be strengthened ; the skeletal 
muscles become heavier, those of the right side keeping 
up the natural advantage over those of the left, as a rule ; 
their strength increases with the work demanded of them 
up to a limit peculiar to each person ; their capacity for 
endurance is enhanced, and their rapidity and precision 
in action are wonderfully augmented (87). Of the micro- 
scopic difference between worked and un worked human 
muscle but little is definitely known. The muscle-bundles 
and sarcolemma of worked cattle are thicker than the cor- 
responding parts in fattening cattle. 

519. Deficiency of Exercise. — Insufficient exercise 
causes the muscles to become smaller and softer, less ener- 
getic in their contraction, less precise in their action, less 
capable of endurance, and less powerful in their combined 
influence. The non-use may lead to excessive wasting, as 
seen in the bandaged limb some weeks after a fracture, or 
even to a change of sarcotic elements (71) into fat, as has 
been noticed after certain nerve-injuries. All the organs 
are influenced by the action of the skeletal muscles. In- 
sufficient action of the voluntary muscles induces feebleness 
and a tendency to degeneracy in most of the tissues and 
organs. 

This want of tone is shown in the pallor, coldness, dry- 
ness, and transparency of the skin ; in the want of color of 
the mucous surfaces ; in the dry and lustreless condition of 

519. Effect of insufficient exercise? Of no exercise? How does 
deficiency of exercise make itself known? What parts do not 
suffer ? 



THE MOTOR APPARATUS AND LOCOMOTION. 313 

the hair ; in the softness and flabbiness of the flesh ; in the 
inability for sustained moderate exertion ; in the ease with 
which irregular and difficult heart-action is induced; in the 
" shortness of breath" and the quickness of respiratory ex- 
liaustion ; in the want of appetite and of ability to digest 
ordinary food ; in the torpor of the bowels ; in the de- 
ficient action of the kidneys ; and in the state of the 
nervous system, characterized by indecision, want of buoy- 
ancy, and a feeling of inadequacy to cope with ordinary 
daily obstacles. 

520. Systematic Exercise. — The term ^' exercise" is 
usually restricted to the action of the skeletal muscles, but it 
should include the indirect culture of the nerve-centres and 
other organs by systematic movements. Of the importance 
to all persons of daily muscular exercise there can be no 
question. The object of systematiG exeTcise is the develop- 
ment and maintenance of a sound, symmetrical organism. 

521. The daily work of the blacksmith develops and 
strengthens the muscles of the arms and trunk, and espe- 
cially the muscles of the right side ; the work of the farm- 
laborer calls into action all the muscles, but some sets pro- 
portionally more than others ; the drill of the dancer, those 
of the limbs; the work of the shoemaker, those of the 
arms; the practice of the boxer, those of the chest and 
arms, etc. In most cases, certain parts of the system be- 
come well or even excessively developed, while other 
equally important parts lag behind in growth and vigor. 
The heart- and lung-development of the blacksmith and la- 
borer, the npper-extremity-culture of the dancer, the heart-. 



520. What is sj'stematic exercisG? Its object? 
521 Give examples of one-sided development. AVliat may result 
from it? 

o 27 



314 ANATOMY, PHYSIOLOGY, AND PIYGIENE. 

lung-, and lower-extremity-clevelopment of the shoemaker 
and other persons following a sedentary line of work, are 
not proportional to those of their best physical parts. As 
the strength of the cable is only that of its weakest link, 
so the capabilities of the human body are only those of the 
weakest part, called into action. If there is a one-sided 
physical development, then will the strong part, in the 
fulness of its power, tend to call upon the weak part for 
a sudden, sustained exertion beyond its power. The weak 
part endeavors, struggles, falters, wavers, breaks, and the 
whole structure topples, even in its apparent prime. It 
has been frequently noticed that the muscularly strong man 
often fails in life's work, where the weaker yet uniformly 
developed though perhaps not completely sound man suc- 
ceeds. Too often the noted boxer, the heavy hitter, the 
successful oarsman, the celebrated gymnast, overtaxes the 
non-developed part, especially the heart and lungs, and in 
a few months becomes a physical wreck. 

522. The Demands of Modern Life require a uni- 
formly-developed, well-consolidated, well-balanced organ- 
ism. It is a sound body, rather than a strong body, that is 
wanted. It should be the aim to establish such an ac- 
cordance between heart, lung, muscle, stomach, kidney, 
and skin as will enable the possessor of the organism to 
perform the duties of life efficiently, regularly, and without 
marked physical inconvenience. 

523. Physical Culture. — Homer observed that no man could 
acquire greater fame than by being strong in his hands, feet, and 
limbs. The Greeks aimed at the harmonious development of the in- 
dividual. In their gymnasia, physical exercises were prescribed and 

522. What is demanded by modern life ? What constitutes a sound 
body ? 



THE MOTOR APPARATUS AND LOCOMOTION. 315 

regulated by law. Incessant methodical drill of the men for war was 
the normal condition of the Eoman commonwealth. The army was 
named, from its dominant occupation, exercitus. In the age of 
chivalry, among the few, a high estimate was placed on the pos- 
session of a perfect body, and great care was observed in its attain- 
ment. With the advent of gunpowder, and the wide acceptance 
of the Church's doctrine of body-mortification in order to soul-per- 
fection, there grew up a disregard of the conditions favorable to 
the body's well-being. This state of darkness prevailed on the con- 
tinent of Europe until the present century, when Ling succeeded in 
introducing the "Swedish movement-cure." Primarily, this was 
designed to meet the needs of every imaginable disease, and had a 
certain measure of success. His followers developed out of it the 
modern system of light gymjiastics. After the humiliation of Jena 
and Auerstadt (October, 1806), Stein devoted himself to the task of 
building up Prussia, of gaining more personal and property free- 
dom for her masses, of elevating her serfs to citizens, of curbing the 
tyranny of caste, of developing an effective militia, and of acquiring 
territory. About the same time, a system of physical training, de- 
signed for the development of strong, serviceable men, was intro- 
duced in Prussia by Jahn. Strange as it may seem, this system of 
physical culture was opposed by the government, on the ground that 
it made the people less manageable and more intolerant of Church 
and State.. But the people appreciated it. It grew in popular favor. 
The enthusiasm for body-training so advanced that in 1853 the Prus- 
sian government made " turning'' a recognized branch of public in- 
struction. Is it not fair to infer that the success of Prussia in Den- 
mark, Austria, and France was quite as much due to the systematic 
general training of her people as to the carrying out of the civil 
systems of Stein ? In England, more than in any other country in 
the world, sports have had a strong hold on the popular mind. All 
classes, the laboring class perhaps excepted, have always shown a 
great practical interest in Avalking, running, wrestling, swimming, 
riding, and other out-door exercises. The result of this is seen in 
the fine physical development of both sexes of the English upper 
and middle classes. The habits of exercise deeply impressed in 
cold, damp England follow them, and appear in their daily life in 
the enervating climates of Asia and Central Anun-ica. The daily 
walk, ride, run, and other vigorous exercises, as well as the '' tub," 



316 AXATOMY^ PHYSIOLOGY, AND HYGIENE. 

are characteristic of the energetic, pushing, enduring Anglo-Saxon 
the Avorld round. 

524. Eelative Advantages of the Systems. — The Swedish 
system, in which the exercises are limited to extremely simple al- 
though varied motions, undoubtedly gives rise to a moderate amount 
of muscular culture. Its routine, however, soon becomes monoto- 
nous. It does not call for that culture of the sense of muscular 
equilibrium, for that concordant action of the eye, of the central 
nervous system, and of the intellectual faculties, which are so highly 
desirable in the training of a sound body. 

The English system, as its training takes place out of doors and 
in the country principally, and as it calls the eye, the brain, and 
the central nervous system into interested action, has much to com- 
mend it. It cultivates the muscular system; it calls for perse- 
verance ; it engenders courage, quickness to see and to decide, and 
celerity in action. It, however, tends too often to a one-sided cul- 
ture, as the mountain climber, the runner, the wrestler, the rower, 
the rider, etc., is inclined to confine himself to the continued cul- 
ture of his peculiar advantage, and becomes highly proficient in 
that respect, but neglects the culture of his weaker parts. Again, 
the English system requires conditions which are not easily attain- 
able by the middle classes of the large towns. 

The German system presents an ideal aim, — uniform, systematic 
culture. It is graded and adapted to every age and condition. It 
can be practised by all classes, even though living in densely-popu- 
lated towns. It tends to a more equable perfecting of the muscular 
and sensory motor systems than either of the other systems. 

525. Influence of Physical Culture. — The census of 1880 
showed that physical culture was a part of the school curriculum 
in three schools per one thousand in the United States. The bodily 
condition of many of the graduates of the high schools, public 
academies, private schools, and colleges is too well known to call 
for comment. That the want of physical training and a lack 
of knowledge as to personal care are largely responsible for the 
decreased eflaciency of the educated young men and women of 
America, is beyond question. At Amherst College, early in the 
fi'eshman year, a knowledge of the human body and of its require- 
ments is inculcated, and throughout the collegiate course physical 
culture is a required part of the student's work. The result of this 



THE MOTOR APPARATUS AND LOCOMOTION. 317 

training is shown in the higher regard which the students have for 
their personal physical condition and hygienic surroundings ; in a 
falling off in the ratio of sickness and invalidism, and a decrease in 
the proportion of three sick in the freshman year to one sick in the 
senior year, as the result of a four years' course. The statistics of 
certain schools for physical culture show that in classes made up of 
college students, school-boys, and city young ladies, under a six 
months' training, there was an increase of about two inches in the 
passive girth of the chest, of four inches in the expansive power, 
and of fifty cubic inches in the lung-capacity, besides a marked 
change in other parts of the system. Figures cannot begin to ex- 
press the change in the physical and mental tone, resulting from the 
use of more air and a better digestion of the food taken, following a 
systematic- drill. 

526. Suppression of By-Motions. — Watch a boy, 
strong in the arms, but unaccustomed to rope-climbing, 
attempt to ascend a rope hand over hand. He begins 
vigorously, but soon falters and struggles ; his muscles 
tremble ; his face becomes contorted ; his legs perform 
choreic movements ; his breath grows labored and irregu- 
lar, and suddenly he descends. After a few weeks' drill 
he is seen to ascend the rope with comparative ease, the 
facial muscles calm, every joint locked, respiration labored, 
but regular. His training has enabled him to suppress 
by-motions, to concentrate his powers on the necessary 
motions, and, as a result, he accomplishes his task easily, 
promptly, and with the expenditure of much less energy. 
The suppression of by-motions, the accurate execution of 
the essential motions, the correct co-ordination of all the 
movements to the given end, and the apparent ease of 
execution, make the postures of the Japanese " geisha," the 
feats of the gymnast, the precision of the soldier, and the 
stroke of the billiard-player pleasurable sights. 



626. What of by-motions ? What does training accomplish ? 

21^ 



318 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

527. Judicious Systematic Exercise makes the mus- 
cles stronger, more agile, and more enduriDg; the extremi- 
ties more flexible, efficient, and obedient; the skin more 
supple and a better protection ; the central nervous system 
better fitted for complicated efforts ; and the mind better 
able to increase its own powers for work and endurance. 
The usefulness of such a training is experienced in many 
situations in life. In emergencies of unexpected danger, — 
fire, shipwreck, accidents by carriage and rail, etc., — the 
superiority resulting from that presence of mind and fer- 
tility of resources which are conferred by the conscious- 
ness of physical strength and trained nerves and rapid 
action makes this training of inestimable value. 

528. Conditions for Exercise. — By exercise is to be 
understood the frequent repetition of a more or less com- 
plicated action of the body, with the co-operation of the 
mind, for the purpose of being able to perform it better. 
During exercise the action of the lungs must be perfectly 
free. The clothing must be so arranged as to preclude the 
least impediment to the free play of the chest and abdo- 
men. The amount of pure air supplied must be unlimited : 
hence it is better to exercise in an open shed, or entirely 
out of doors. 

As soon as the respirations become labored, or if there 
be sighing respiration, rest must be taken. The heart 
should be gradually accustomed to its work. In order to 
bring the heart's action and the lungs' capacity to take the 
blood into accord, all exercise should be entered upon 
slowly and gradually. The breath lessness of the untrained 



527. What results from systematic exercise ? What advantage? 

528. What is exercise? What primar^^ conditions ? What signs 
of danger? Management? What of the heart-action? What of 
the skin? Of shoes? Of food ? Of drink? 



THE MOTOR APPARATUS AND LOCOMOTION. 319 

runner who starts off at the height of his speed is due to 
blood congestion of tlie lungs. Hence, in endeavoring to 
reach a firCj with the intention of doing good, ^^ make haste 
slowly.'' The heart's action must be closely watched. Ex- 
cessive rapidity of the pulse (one hundred and twenty to 
one hundred and forty beats in the minute), or inequality 
or irregularity of the beats, points to the need of rest, and 
later to a more gradual order of exercise. Occasionally, a 
sudden excessive effort leads to rupture of the walls of the 
heart. 

The skin should be kept very clean. During exercise 
the skin may be thinly clad. In tlie intervals of exertion, 
and immediately after, it should be so well covered as to 
prevent the least feeling of coolness of its surface. Flannel 
is best adapted for an exercise suit. The shoes should give 
plenty of room all around the foot; the sole should be 
thinnest and narrowest at the ^^ waist," where elasticity is 
wanted, should be broad and thick at the " tread," where 
protection is most required, and the heels should be low 
and broad. A well-formed large foot is a far pleasanter 
sight than the smallest one distorted. 

Food should not be taken immediately before or directly 
after exercise. Water is the best fluid to train on. Cold 
water may be taken moderately, and often, during exercise. 
When overheated, it is best to wash out the mouth fre- 
quently, and later to drink moderate amounts. 

529. Rest (425) is essential at frequent and regular in- 
tervals. The length of the period of rest should be such 
as to enable the muscles to regain their tone and to work 
with ease and vigor. The interval of rest enables the blood 

529. What of the leiijxth of the periods of rest? What is the 
object? Management after exercise? 



320 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

to remove the products of tissue-change from the centres 
of activity (muscle- and nerve-ganglia), and to permit tlie 
system, especially the muscles, to lay up a new store of 
oxygen, for during action the oxygen brought in the blood 
is not sufficient for the demand of the fleshy elements (87). 
After exercise, sponging with tepid water to remove the 
dust and the dried products of perspiration, vigorous rub- 
bing, and putting on a dry under-suit are advisable. 

530. Kinds of Exercise.— The kinds of exercise 
should be selected according to the physical wants of the 
individual. The object in all cases is the production and 
the keeping up of a sound, well-balanced organism. The 
exercises suitable for a given individual can be determined 
only after a physical examination and a consideration of 
the evident needs of the system. The hap-hazard method 
of taking up a line of exercise is not judicious. For 
a beginner, the exercises should be carefully prescribed 
and the conditions for exercise clearly laid down. All 
exercise, to be beneficial, must be pleasurable and give 
buoyancy to the mind as well as strength to the muscles. 
Walking, to be beneficial, should l)e so active as to excite 
free perspiration in ordinary weather. Croquet and the 
" constitutional walk^' of the boarding-school file are of 
little physical benefit. In quick walking, running, and 
rowing (especially with the slide-seat), the work is mostly 
performed by the muscles of the trunk and lower limbs, 
and hence they should be supplemented by a line of move- 
ments calling the upper extremities into action, like Indian 
clubs, rope and ladder exercises, etc. Base-ball, cricket. 



530. What is the object of exercise? How best effected? What 
of hap-hazard exercise? Of mental interest? Of walking ? Of 
sports ? Of lawn tennis ? Of gardening ? Of household work ? 



THE MOTOR APPARATUS AND LOCOMOTION. 321 

swimming, skating, boxing, wrestling, and the riding of a 
restive horse are most excellent forms of exercise. Lawn 
tennis, from a hygienic point of view, is the best of modern 
games. It calls into action the eye, the intellectual and the 
motor centres, and makes demands on most of the muscles 
of the body, and is therefore to be commended, especially 
for ladies. Daily work in the garden is a good form of 
exercise, if the person performs all the kinds of work 
there afforded. No kind of exercise is so well calculated 
to develop all parts of the body in woman, and to pro- 
mote good health, as housework. The development of a 
well-knit frame, of firm fat, and of muscular strength 
should be encouraged in girls. Their health and happiness 
are not only promoted, but they will be better fitted for 
one of woman's most exalted missions in life, — maternity. 
531. The Amount of Exercise should be adjusted to 
the age and physical condition of the person. All move- 
ments must be kept within the strength and capacity of 
the given individual. All exercise should stop short of 
muscular exhaustion. In infancy, freedom of movement 
should be allowed. The child ought not to be urged to 
walk because it has passed a certain number of months. 
Compelling a child to walk at an early date often leads to 
deformed legs and feet. Boys and girls should take part in 
the same sports, be trained in similar duties, and be required 
to take part in the same occupations. In after-life it will 
be of as much advantage for the boy to have a definite idea 
of in-door duties as for the girl to be acquainted with 
out-door pursuits. Prolonged, severe efforts should not 



531. What general rule ? Speak of exercise for infants. For 1h\vs. 
For girls. For young men and Avonien. What is Dr. Parkess con- 
clusion ? Speak of exercise for business-men. For invalids. 

V 



322 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

be demanded until the system is consolidated (about the 
twenty-first year). Young, immature men, subjected to the 
strain of a military life, easily succumb to fatigue, as did 
the later conscripts in the French armies of Napoleon I. 
During the period of early manhood and womanhood, 
such an amount of out-of-door exercise, in addition to 
daily duties, should be taken as will daily induce healthy 
sleep from 9 p.m. until 5.30 a.m. Dr. Parkes estimates 
that every healthy adult man ought, if possible, to take a 
daily amount of exercise in some way which shall not be 
less than one hundred and fifty tons lifted one foot. This 
amount of work is equivalent to a walk of about nine miles 
on the level. As ordinary daily occupations call for cer- 
tain amounts of effort, probably a daily walk of five miles, 
in addition, would be sufficient exercise for a business-man. 
The amount and kind of exercise for invalids should be 
determined by the medical attendant. After illness the 
convalescent should use caution, so as not to exceed his 
slowly-gaining powers of body and mind. A slight over- 
exertion is very frequently the cause of a relapse in fevers. 
532. Posture. — An erect posture in sitting and in walk- 
ing should be maintained. The erect, easy carriage of 
the West Point cadet results from the careful, persistent 
drill on the parade and in the class-room and study-room. 
It is commenced in youth and is continued through early 
manhood, and, as a result, the bones are consolidated in 
correct positions and the muscles of the right and left sides 
become equally developed. The uniform drill of the mus- 
cles, especially those of the back and abdomen, in child- 
hood and youth would dispense with the demand for corsets 



532. Wliat is the West Point training ? Why are corsets in great 
demand ? What of distortions ? 



THE MOTOR APPARATUS AND LOCOMOTION. 323 



and braces by the young and middle-aged of both sexes. 
For the want of proper exercise, distortion of the chest and 
spine often appears. It has been affirmed that, among the 
fashionably educated, not one woman in ten escapes deform- 
ities of the thorax and spine, followed by lung and heart 
troubles. Assuming improper positions for several hours 



Fig. 133. 



Fig. 134. 




Fig. 133 represents an Improper, but not an unusual, position when writing. 
Fig. 134 represents a Proper position when writing. 

daily, tlirough a series of years, as is too often done by 
students, certain artisans, seamstresses, etc., together with 
one-sided exercise, does not fail to produce distortion. 

533. It has been noticed that slate-carriers and porters, 
who carry burdens on their heads, unsupported by the 
hand, are erect, well-balanced men. The drill of carry- 

538. Effect of currying weights on the lioad ? Wluit may a student 
do to his own advantage ? Test ? 



324 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



Fig. 135. 



ing a book balanced on the head at intervals during the 
day cannot fail to be beneficial to students. Students 
should, at frequent intervals during the day, rise, loosen 
the garments about the thorax and abdomen, take several 

deep respirations, then place 
the palms together in front 
of the chest, on a level with 
the fourth rib, and sweep 
them in that plane around 
to the rear, endeavoring to 
strike the knuckles together. 
Repeat this several times. 
Upon rising, and before re- 
tiring, stand erect, heels to- 
gether, the feet forming an 
angle of ninety degrees; 
raise the hands vertically 
over the head, fists closed, 
thumbs in contact, then, 
bending the back, endeavor 
to touch the floor with the 
knuckles w^ithout bending 
the knees. Eepeat this sev- 
eral times. Test — Stand erect, with the back to the wall 
of the room and the back of the head in contact with the 
same. The ease with which this can be done will gauge 
the progress towards an erect attitude. 

534. Training. — The object of training is to increase 
the breathing-power, to co-ordinate the heart-power to the 
blood-taking capacity of the lungs, to make the muscular 




Fig. 135. A Deformed Thorax and 
Spinal Column. 



534. "What is the object of training? How is it accomplished? 
What results ? "What may then be done ? 



THE MOTOR APPARATUS AND LOCOMOTION. 325 

action more vigorous and enduring, to increase the action 
of the eliminating organs, especially of the skin, and to 
lessen the fat. This is accomplished by a course of gradu- 
ated exercises, such as induce free perspiration, with a diet 
rich in proteids but restricted as to carbo-hydrates, by care 
in the selection of beverages (water is best), and by absti- 
nence from dissipation and from the use of stimulants and 
tobacco. The result of several weeks' work is a greater 
tissue-waste, a greater demand for proteids, fats, and pure 
air, a quicker renewal of the tissues, and a more vigorous 
living. A higher condition of health ensues. If, for the 
given individual, this is not carried to excess, the system 
can accomplish a severe, sustained physical exertion with 
greater safety than before the training. '^ The lives of 
most men are in their own hands, and, as a rule, the just 
verdict after death would be/e/o de se." 



CHAPTER Xy. 

CARE OF THE SICK AND EMERGENT CASES. 

535. In^ every home, however humble or dignified, woman is 
usually the Nurse. Nature seems to have endowed her in an es- 
pecial manner to minister at the couch of disease and suffering. 
To be a good nurse requires a high type of womanhood ; she should 
have both mental and physical power, blended with integrity and 
Christian trust. 

If " good nursing is half the cure," how important that the 
daughter be early taught how to prepare drinks and nourishment, 
to administer medicine, and to perform the varied and important 
duties of the faithful nurse ! 

The physician well knows that his attentions upon the sick are 
unavailing unless the nurse obeys his directions. For a nurse, or 
immediate relatives or friends of the sick, to put their judgment 
in opposition to that of the physician, is not only arrogant, but 
endangers the patient. 

The room for the sick should be selected where sunlight may 
enter, and as far from external noise as possible. It is poor 
economy, not to say unkind, to keep a sick man in a small, ill- 
arranged bedroom, when a more spacious and airy room is kept 
for only occasional " callers." All superfluous furniture should be 
removed from the sick-room. 

536. In the first stages of disease, it is always proper treatment 
to rest both body and mind. It is wrong to tempt the appetite of a 
sick person : the disinclination for food is the warning of Nature 
that the system cannot well digest it. 

The beneficial effects of bathmg can hardly be overestimated, 
but the mode of the bath should be directed by the medical ad- 
viser. The best time, however, for bathing is when the patient 
feels most vigorous and is freest from exhaustion. Care is necessary 
to wipe dry the skin, particularly between the fingers and toes, and 
326 



CARE OF THE SICK AND EMERGENT CASES. 327 

also the flexures of the joints. Friction from a brush, a moreen 
mitten, or a dry flannel that has been saturated with salted water 
tends to relieve restlessness in patients. Air-baths have a tran- 
quillizing influence. 

537. Quiet should reign in the sick-room. No more persons should 
enter or remain in it than the welfare of the patient demands. It 
is the duty of the physician to direct when visitors should be ad- 
mitted or excluded, and the nurse should enforce the directions. 
The movements of the attendants should be gentle : there should 
be no bustling to arrange the room at a fixed time ; this should be 
done quietly and when it will give the least annoyance to the sick 
person. When a room requires sweeping, scatter over the carpet 
drained coflee-grounds ; then keep the broom before you, giving a 
light, short brush ; the dust will thus be prevented from rising above 
the couch. (It may be necessary to use a damp cloth in dusting the 
furniture, especially if the patient has disease of the lungs.) Creak- 
ing hinges should be oiled ; shutting doors violently and heavy 
walking should be avoided. All unnecessary conversation should 
be deferred. If a colloquy must be carried on, let the tone be so 
high that the patient, if interested, can thoroughly comprehend it. 

538. The making of the bed is often badly conducted. All 
bunches should be removed, the material of the bed laid even, and 
a thin quilt spread smoothly over a mattress. When convenient, 
have the head of the bed northerly, and so situated, at least, that 
the sick person may look on something more pleasurable than a 
table of glasses and phials. A nurse should never manifest impa- 
tience in arranging the pillows, but should try to adapt tliem to the 
comfort of the weary patient. 

539. All utensils employed in the sick-room should be kept clean. 
Water designed for the patient to drink should not stand long in 
an open glass or pitcher, but, if convenient, should be given fresh 
from a spring or well. A very sick person is fatigued by being- 
raised to receive drinks ; hence, a bent tube or a cup Avith a spout 
should be used. 

Both the apparel and the hcd-lineu should be changed more fre- 
quently in sickness than in health, and oftener in acute than in 
chronic diseases. All clothing should be well dried and warmed by 
a fire previous to being put on the bed or the patient. 

No agent is of more importance to the sick-room than pure air ; 



328 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

hence the nurse, with all convenient speed, should remove every- 
thing that can emit an unpleasant odor. She should be chary of 
keeping ripe fruit or bouquets of flowers any length of time in the 
sick-chamber. When a disinfectant is needed, procure at the drug- 
gist's chloride of lime. To change quickly and effectively the air 
of the sick-room, cover the patient's bed with an extra blanket and 
closely envelop his head and neck, except the mouth and nose ; the 
door and windows can then be safely opened for a short time. After 
the windows are closed, retain the extra coverings on the patient 
until the room is of proper warmth. Unless duly protected, the 
patient should never feel currents of air, although fresh air should 
be constantly admitted into the sick-room. 

A well-adjusted thermometer is indispensable, as the feelings of 
the patient or nurse are not to be relied on as a true index of the 
temperature of the room. Eegulating the warmth of the patient 
is one of the many duties of the nurse. There is a " sweating tem- 
perature ;" when this is exceeded, perspiration will cease, if it has 
been present ; also it will not take place during a high tempera- 
ture. The patient should no more be allowed to complain of too 
much heat, without an attempt at its reduction, than he should be 
permitted to remain chilly when a change is possible. 

540. The nurse should not confine herself to the sick-room longer 
than six hours at a time. She should exercise daily in the open 
air, also eat and sleep as regularly as possible. No doubts or fears 
of the patient's recovery, either by a look or by a word, should be 
expressed by the nurse in the chamber of the sick. 

541. Medicines assist the natural powers of the system to remove 
disease. They should be given regularly, judiciously, and with 
cheerfulness. Life itself is often at the mercy of the nurse, and 
depends on the faithful discharge of her duty. 

542. Brinks have a more decided influence upon the system than 
is generally admitted ; hence the nurse should never depart from 
the quality of the drink, nor even exceed the due or prescribed 
quantity. Giving " herb-teas" without the sanction of the physi- 
cian may cause serious evil. 

543. The food of the sick should be prepared in the neatest and 
most careful manner, and the nurse ought to obey implicitly the 
physician's directions about diet. When a patient is convalescent, 
the desire for food is generally strong; great care, firmness, and 



CARE OF THE SICK AND EMERGENT CASES. 329 

patience are required, that the food be prepared suitably and given 
at the proper time. 

We append a few modes of preparing nourishment for the sick. 

Crust Coffee. — Take light, sweet bread or crackers, and brown 
them thoroughly, as you would coffee-berry ; when wanted for use, 
pour on them boiling water (the crusts will admit of several replen- 
ishings of boiling water) ; add sugar and cream to suit the condi- 
tion of the patient. 

Gruels. — Corn-meal requires to be boiled several hours to be 
suitable nourishment for the sick. The mode of preparing gruel 
should be suited to the case and directed by the physician. Wheat- 
flour or oat-meal, farina, and sago can be prepared in less time, 
though they must be well cooked. Add salt while cooking. 

Egg Gruel. — Take the yelks of two hard-boiled eggs; with a 
knife reduce them to a fine powder; beat this in a milk gruel 
made of rich new milk and wheat-flour ; spices may be added when 
the condition of the patient permits. 

Beef Tea. — Meat contains principles that may be extracted, 
some by cold, others by warm, and still others by boiling, water ; it 
should be cut very fine, and submitted for three hours each time, 
in succession, to half its weight of cold, of warm, and of boiling 
water ; the fluids strained from the first and second macerations are 
to be mixed with that strained from the boiling process, and the 
mixture should be brought to a boiling heat to cook it ; skim off" 
the fat, and add a few drops of lemon-juice, with salt, for a flavor. 
Many of the " prepared foods" are to be commended. 

Food for a Babe. — Cow's milk (Ayrshire is preferable) is a 
substitute for healthy human milk. In feeding — 1st, let the babe 
draw from the bottle warmed ivater to its satisfaction ; 2d, after 
a few minutes give it fresh, undiluted, properly-warmed milk to 
which a trace of salt has been added ; 3d, have it suck very slowly 
all it will take. Some infants thrive on suitable diluted or con- 
densed milk. Starchy or fibrous food should not be given until 
the child is seven months old. 

544. Poultice. — Mix the corn- or linseed-meal into a paste 
with hot water. On a piece of folded cloth place the paste to the 
thickness of half or three-fourths of an inch. Leave at least an inch 
of free margin between the paste and the edges of the cloth. On 
the upper surface place apiece of nuislin or mosquito-netting of the 

28* 



330 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

size of the surface of the paste. Now fold the free edges over the 
edges of the netting. Apply the netting side to the skin. On the 
outside place a layer of oiled paper, or oiled silk, or gum-cloth. 
If the wound is painful, sprinkle a few spoonfuls of laudanum over 
the poultice ; if the wound is offensive, mix powdered charcoal in 
the paste. 

545. Olive Oil. — In chest-diseases. Dr. Von Gieth, of Munich, 
uses olive oil in preference to poultices. Take a double fold of 
cotton cloth, sufficiently large to surround the trunk completely. 
Thoroughly saturate this with warm olive or cotton-seed oil. Apply 
this closely to the chest, shoulders, and abdomen. Over all draw a 
loose woollen shirt. Kenew from time to time. The oil softens the 
skin and retains in the chest a uniform amount of heat. 

546. The duty of the Watcher is scarcely less responsible than 
that of the nurse, and, like the nurse, she should ever be cheerful, 
kind, firm, and attentive in the presence of the patient. 

The watcher should be prompt, and reach the house of the sick 
at an early hour. Before entering the sick-room, she should eat a 
simple, nutritious supper, and also during the night take some plain 
food. She should be furnished with an extra garment, as a heavy 
shawl, to wear towards morning, when the system becomes ex- 
hausted. 

The directions about the sick, especially the administration of 
medicine, should be written for the temporary watcher. Whatever 
may be wanted during the night should be brought into the sick- 
chamber or the adjoining room before the family retires to sleep, 
so that the slumbers of the patient shall not be disturbed by haste 
or searching for needed articles. 

Sperm candles are preferable for the sick-room. Kerosene, in 
burning, emits a disagreeable odor, often annoying to the patient. 
All lights ought to be so arranged as not to be reflected in the part 
of the room where the sick person lies. 

It is not necessary that watchers make themselves acceptable to 
the patient by exhausting conversation. If two watchers are needed, 
it is more imperative that they refrain from talking, and particu- 
larly from whispering. 

Most sick persons have special need of nourishment about four 
or five o'clock in the morning. 

547. When taking care of the sick, light-colored cotton or linen 



CARE OF THE SICK AND EMERGENT CASES. 331 

clothing should be worn in preference to worsted apparel, especially 
if the disease is of a contagious character. It is always safe for the 
watcher to change her apparel worn in the sick-chamber before 
entering upon her family duties. Disease is often communicated 
by the clothing. 

It can hardly be expected that the farmer who has been laboring 
hard in the field, or the mechanic who has toiled during the day, 
is qualified to render all those little attentions that a sick person 
requires. Hence, would it not be more benevolent and economical 
to employ and pay watchers who are qualified by knowledge and 
training to perform this duty in a faithful manner, while the kind- 
ness and sympathy of friends may be practically manifested by assist- 
ing to defray the expenses of these qualified and useful assistants ? 

POISONS AND THEIR ANTIDOTES. 

548. Poisoning, either from accident or from design, is of such 
frequency that every household should keep some available remedy, 
and every person should know what to do in such alarming contin- 
gencies. Nearly every poison has its antidote, which, if used at 
once, may prevent much suffering, and even avert death. 

When known that poison has been taken into the stomach, the 
first thing is to evacuate it by the use of the stomach-pump or an 
emetic, unless vomiting takes place spontaneously. 

As an emetic, ground mustard mixed in warm water is always 
safe. Take one tablespoonful to one pint of warm water. Give the 
patient one- half in the first instance, and the remainder in fifteen 
minutes if vomiting has not commenced. In the interval, let him 
drink copious draughts of warm water. Tickle the throat with a 
feather or the finger, to induce vomiting. After vomiting has be- 
gun, give mucilaginous drinks, such as flaxseed tea, gum-arabic 
Avater, or slippery-elm water. 

If the patient is drowsy, give a strong infusion of cold coffee, 
keep him walking, slap smartly on the back, use electricity ; it may 
be well to dash cold water on the head, to keep the patient awake. 
After the poison is evacuated from the stomach, to sustain vital 
action, give warm water and wine or brandy. If the limbs are 
cold, apply warmth and friction. 

In ALL cases of poisoning, call a physician inimodiately, as the 
after-treatment is of great importance. 



332 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



549. 



Poisons. 



Aconite (Monkshood). 
Belladonna (Deadly Nightshade.) 
Bryony. 
Camphor. 

^°°2"'}(^^'^t*'>- Hemlock). 

Croton Oil. 

Digitalis (Foxglove). 

Dulcamara (Bitter-Sweet). 

Gamboge. 

Hyoscyamus (Henbane). 

Laudanum. 

Lobelia. 

Morphine. 

Opium. 

Paregoric. 

Sanguinaria (Blood-Root). 

Savin Oil. 

Spigelia (Carolina Pink). 

Stramonium (Thorn- Apple). 

Strychnine (Nux Vomica). 

Tobacco. 

Arnica. 



Antidotes or Remedies foe Poisons. 



For vegetable poisons give an 
emetic of mustard; make 
the patient drink freely 
of warm water; tickle the 
throat with a feather, to 
induce vomiting. Keep the 
patient awake until a phy- 
sician arrives. Administer 
strong coffee freely. 



Vinegar and water. 



Prussic Acid. 

Bitter Almonds (Oil of). 

Laurel-Water. 



Drink, at once, one teaspoonful 
of wafer of hartshorn (ammo- 
nia) in one pint of water. 



Ammonia (Hartshorn). 

Potash. 

Soda. 



Vinegar or lemon-Juice, fol- 
lowed by sweet, castor, or 
linseed oil. Thick cream 
will answer as a substitute 
for oil. No emetic. 



Iodine. 



Starch or wheat-flour beaten 
in water. Give a mustard 
emetic. 



CARE OF THE SICK AND EMERGENT CASES. 



333 



Poisons. 



Saltpetre (Nitrate of Potassa). 
Chili Saltpetre (Nitrate of Soda). 



Lunar Caustic (Nitrate of Silver). 



Corrosive Sublimate (bug-poison). 
White Precipitate. 
Ked Precipitate. 
Vermilion. 



Arsenic. 

Cobalt (fly-powder). 

King's Yellow. 

Eatsbane. 

Scheele's Green. 



Acetate of Lead (Sugar of Lead). 

White Lead. 

Litharge. 



Antidotes or Kemedies foe Poisons. 

Give, at OTiGe,Simustard emetic ; 
drink copious draughts of 
warm water, followed by oil 
or cream. 

Two teaspoonfuls of table-salt 
(chloride of sodium) mixed 
in one pint of water. 

Beat the whites of six eggs in 
one quart of cold water ; give 
a cupful every two minutes. 
A substitute for white of eggs 
is soap-suds slightly thick- 
ened with wheat-flour. 
Emetics should not be given. 

Use a stomach-pump as quickly 
as possible, or give a mustard 
emetic until one is obtained. 
After free vomiting, give 
large quantities of calcined 
magnesia. The antidote for 
arsenic is hydrated peroxide 
of iron. 

Use a mustard emetic, followed 
by Epsom or Glauber's salt. 
The antidote is diluted sul- 
phuric acid. 



Antimony (Wine of). 
Tartar Emetic. 



Pearl-ash. 

Ley (from wood-ashes). 

Salts of Tartar 



The antidote is ground nuf-gaU, 
or, as a substitute, oak or 
Peruvian bark, followed by 
a tcaspoonful of paregoric. 

Drink freely of vinegar and 
water, followed by a uuiei- 
lage, as flaxseed tea. 



334 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



Poisons. 



Sulphuric Acid (Oil of Vitriol). 
Nitric Acid (Aquafortis). 
Muriatic Acid (Hydrochloric). 
Oxalic Acid. 



Matches (Phosphorus). 
Eat Exterminator. 



Verdigris. 
Blue Vitriol. 



Stings of Insects. 



Charcoal Fumes. 
Illuminating Gas. 
Sewer- Gas. 



Antidotes or Eemedies for Poisons. 

Drink largely of water or a 
mucilage. It is important 
that something be given 
quickly, to neutralize the 
acid. The antidote is cal- 
cined magnesia. Chalk, lime, 
strong soap-suds, are substi- 
tutes for magnesia. 

Give two tablespoonfiils of cal- 
cined magnesia, followed by 
mucilaginous drinks. 



The antidote is cooking- 
or white of eggs. Drink 
milk freely. 

Ammonia, or cooking-soda 
moistened with water, ap- 
plied in the form of a paste. 
The wound may be sucked, 
followed by applications of 
water. 

Fresh air and artificial respira- 
tion (557). 



550. Bleeding, or Hemorrhage. — The bleeding from an arteri/ 
is characterized by the escape of a bright-scarlet frothy stream in 
Jets ; that from a vein, by the trickling of a steady current of dark 
blood ; and that from the capillaries, by oozing from many divided 
points. The former may be controlled by judicious pressure in the 
course of the artery, or by direct pressure at the point from which 
the jets escape ; the venous and capillary bleeding, by elevating 
the part and by pressure applied to the cut surface. Small vessels 
cut directly across readily contract, and the blood-current is natu- 
rally retarded and stopped. Crushed wounds rarely bleed freely. 
Bleeding from large arteries or large veins must be quickly con- 
trolled, or the great loss of blood will occasion death. 



CARE OF THE SICK AND EMERGENT CASES. 835 



551. Management of Bleeding. — If from a large artery, place 
your finger on the jetting spot, elevate the limb, and keep the 
patient quiet ; if from a small artery or vein, elevate the part, and 
wash off the dirt and clots with a stream of water. Apply (1) ice, or 
(2) direct a stream of hot water of a temperature of 46° C. to 49° C. 
(115° F. to 120° F.), — i.e., the water must not be hotter than that in 



Fig. 137. 




Fig 136 Track of the Large Artery of the Arm.— 1, Tho collar-bone. 9, The 
axillaiy artoiy 10, The brachial artery. 

Fig. 137. B, The manner of compressing the artery near the collar-bone. A, The 
manner of compressing the large artery of the arm with tho fingers. C, Tho manner 
of compressing the divided extremity of an artery in the wound with a finger. 



which you can hold the hand, and then gradually incroaso the tem- 
perature by the addition of water slightly hotter. In the ease of 
internal bleeding, the temperature of the water may be raised from 
46° C. gradually to 71° C. (115° F. to 160° F.). ' Use hot Avater 
freely. (8) I]x})()se the part to the air. In the latter case, the natu- 
ral contraction of the artery in connection with coagulation will 



336 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



control all moderate flow. Use no alum, or iron, or tannin, or other 
styptics. They retard future healing. 

When the bleeding is controlled only by direct pressure in the 
wound, then apply the field tourniquet in the course of the artery 
above the wound, after which the finger on the jetting point may 
be removed. To make a field tourniquet, take a square piece of 
cloth, or a handkerchief, twist it corner-wise, and tie a hard knot in 
the middle. Place the knot over the artery, between the wound 



Fig. 1 



Fig. 139. 




Fia. 138. Method of Applying the Knotted Handkerchief to compress a divided 
artery. A, B, Track of the brachial artery. 

Fig. 139. A, C, Track of the femoral artery ; the compress applied near the groin. 



and the heart, carry the ends around the limb, and tie loosely. 
Place a stick under the handkerchief, near the last tie, and twist 
till the fingers can be removed from the compression without a 
return of the bleeding. (See Figs. 138 and 139.) 

652. Having the bleeding under control, let the patient lie in a 
cool open room, with heaters to his feet. Keep him quiet. Keep 
anxious friends away from his side. If he desires, give him some 
nourishing drink, or water, especially the latter. If a surgeon 
cannot be secured, then, with a fish-hook attached to a penholder, 
or with a pair of small toothed pincers, pull out the large artery or 
large vein, and tie a silk or linen thread around the vessel between 
the hook and the flesh, making a "■ reef-knot," and allowing the 



CARE OF THE SICK AND EMERGENT CASES. 337 

long ends to hang out of the wound. Eemove the tourniquet, wash 
the wound, apply ice or hot water to the small bleeding-points, draw 
the parts together, and with a few turns of a bandage secure the 
parts in place. Allow the injured part to rest at ease on a pillow, 
covered with oiled silk, or oiled paper, or india-rubber, for the sake 
of cleanliness. Unless bleeding again occurs, do not change the 
dressing for forty-eight hours. On the third morning, carefully 
remove the stiffened cloths, previously softening them with tepid 
water, and cleanse the wound with warm water. In some cases, add 
to the warm water a little alcohol, or a few drops of carbolic acid. 

Fig. 140. 




Fig. 140. Mannei- of applying adhesive strips to wounds. 



553. In Flesh- Wounds, when no large vessel is divided, wash 
the parts with cold water, and, when bleeding has ceased, draw the 
incision together, and retain it with strips of adhesive plaster not 
more than a quarter of an inch in width. Then apply a loose 
bandage. Avoid all ointments, " healing salves," and washes. In 
removing the dressing from the wound, both ends of the plaster 
should be raised and drawn towards the incision. To lessen the 
liability of a reopening, a proper position for the union should be 
regarded. If the wound is between the knee and the ankle, and on 
the anterior part, extend the knee and bend up the ankle ; if on the 
posterior part, reverse the movement; and, in general, suit the posi- 
tion to the case. In severe wounds of the extremities, — arm or leg, 
— splints of wood or tin, well padded with cotton batting and cov- 
ered with oiled silk, should be a})plied, in order to keep the adjacent 
joints locked and the irritated nuiscles from continually twitching. 
By keeping the parts quiet, the tendency to healing is assisted. 

The union of the divided parts is effected by the action of the 
blood, and not by salves or ointments. The only object of the 
dressing is to keep the parts together and protect the wound from 
air and impurities. Nature performs her own cure. iSmall wounds 



338 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



seldom need a second dressing, and should not be opened until the 
incisions are healed. 

554. Bleeding at the Nose [Epistaxis). — When due to an 
injury, it soon ceases ; when due to plethora, it is often of benefit, 
and should be checked only when it becomes too copious. When 
occurring in a feeble person^ it is often quite serious. 

Management. — Sit 



Fig. 141. 




Fig. 141. «, a, Eepresentation of wounds on the back 
part of the arm and forearm, b, h, Wounds of the an- 
terior part of the arm and forearm. By bending the 
elbow and wrist, the incisions at a, a, are opened, while 
those at 6, h, are closed. Were the arm extended at the 
elbow and wrist, the wounds at a, a, would be closed, and 
those at 5, h, would be opened. 



up. Keep the head 
elevated. Eaise the 
arms vertically at 
full length above the 
head. Breathe through 
the mouth. Have a 
cloth or sponge held 
under the nostrils, but 
do not bend forward. 
Apply ice to the nose, 
the middle of the fore- 
head, and the nape of 
the neck. If it does 
not soon cease, then 
allow a stream of cold 



water, containing a 
teaspoonful of cooking- soda and a teaspoonful of table-salt to the pint 
of water, to flow in at one nostril and out at the other, the mouth being 
kept open all the time. Employ a nasal douche apparatus for this 
purpose. If this fails, and if a surgeon cannot be secured, the 
nostrils must be plugged. Cut a piece of sponge, as large as the 
nostril will admit, in a rounded form. Attach it to a cord. Push 
it into the nostrils as far back as the pharynx (Fig. 38). Make a 
number of similar pieces of sponge. With a darning-needle on the 
cord, thread one piece after another, and force them one by one into 
the nostril, until it becomes filled. This will control the bleeding. 
Eemove after forty-eight hours by pulling out one at a time. Bleed- 
ing from the cavity from which a tooth has been recently extracted 
can be controlled by packing it with a paste of plaster of Paris. 

555. Broken Bones, or Fractures. — While the patient is 
lying on the ground, cut oft" the garments and the boots. Do not 
increase the pain by pulling them off". Gently but firmly pull on 



CARE OF THE SICK AND EMERGENT CASES. 339 

the parts below the fracture until the arm or limb reaches its fiill 
length. Hold it quietly in this new position. This movement will 
pull the bone-fragments from the torn flesh, will prevent sharp, 
painful muscular contractions, and will give the patient some ease. 
Let another procure some thin strips of board, or lath, or straight 
sticks, or hollowed pieces of tin or sheet-iron, or even common 
straw cut to the length of the limb. Place some cloth or grass, 
in the form of even pads, above and below the broken part, then 
adjust around the parts a layer of the sticks, -or laths, or bits of 
shingle, or straw, and then secure them above and below the break 
by cords or straps. Permit the splints to extend beyond the joints 
above and below. Now the man may cease pulling on the limb, 
and the patient can be transported home with comparatively little 
suffering, even in a springless wagon. A person suffers less when 
borne by two or four men on a shutter than in an ordinary hack or 
express-wagon. At home, the patient should be placed on a mat- 
tress which rests on slats. The spring, the wire, or the rope bed- 
stead is not well adapted for the treatment of fractures of the 
lower extremities. Place a thick quilt on the mattress, then a 
rubber sheet, and a cotton sheet over all. When the bones have 
been adjusted as nearly as possible in position, the surgeon's work is 
not done. The keeping of the parts in the proper position demands 
daily educated care for several weeks. Hence the surgeon should 
be retained until the parts are again consolidated in the position 
found most practical. A broken bone can rarely be made as good, 
in form, shape, position, and usefiilness, as the uninjured bone. 
The bad results in the treatment of many fractures are more de- 
pendent on the wilfulness, irritability, and meddling of the patient 
than on want of skill on the part of the surgeon. 

556. Burns and Scalds. — A burn is caused by the application 
of concentrated heat to the body ; a scald, by the application of hot 
or boiling liquids. The effect varies according to the intensity and 
duration of the application. It ranges from simple redness to de- 
struction of the part. The extent of the surface involved is also 
an important factor. When more than half the body is involved, 
death usually results. 

When only a small patch ol" (ho skin is involved, in order to 
prevent blistering, apply coA/ water continuously until the smarting 
ceases, or plunge the part in a basin containing water and cooking- 



340 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

soda. Cut off garments whicli are in contact with the injured 
parts. Use care, so as not to remove the epidermis. Prick the 
lower outer edge of the blisters, and allow the water to run out. 
In moderate burns and scalds, apply cloths soaked in water con- 
taining all the cooking-soda it will dissolve. Do not remove the 
cloths, but keep them constantly wet. If cooking-soda is not at 
hand, apply strong soap-suds. The alkali of the soap soon deadens 
the pain. If the burn is extensive, put the patient into a warm 
bath, and raise the temperature of the water until he is comfort- 
ably warm. Give him some hot alcoholics and some opium prepa- 
ration. After extensive burns, as from coal oil, the hot bath is 
the best place to live and to sleep in. 

Do not remove the dressings for some days, — not until they are 
loosened by the discharges, or until they become very offensive. 
When the first dressing is removed, the character of the injury will 
determine the subsequent dressing. It may be carbolic acid in sweet 
or cotton-seed oil, one part to ten ; or zinc ointment ; or equal parts 
of lime-water and linseed oil ; or flour dredged on the surfaces. In 
all cases keep the patient warm, give nutritious foods, administer 
alcoholics and opium as needed, and keep the parts quiet and 
clean. To prevent deformities, follow the instructions of the sur- 
geon as to position and dressings. 

557. Asphyxia, as from drowning or from breathing illuminating 
gas, etc. — Treat the patient at once, and on the spot. Place him 
in an open space. Do not permit the people to crowd around. 
Eemove all obstructions to the passage of air to and from the lungs 
by cleansing the froth and mucus from the mouth and nostrils. If 
the person has been pulled out of the water, raise him up by the 
limbs, to allow all fluids to escape. If he has been pulled out of an 
atmosphere of choke-damp, of gas, of charcoal fumes, of chloroform 
or ether vapors, elevate the extremities, in order to assist the flow 
of blood towards the head and heart. Remove all close-fitting 
articles of clothing from the neck and chest. If natural respiration 
has ceased, employ the Silvester Method, as follows : 

558. (1.) The body being laid on its back (either on a flat surface, or, better, on a plane 
inclined a little from the feet upward), a firm cushion or some similar support should be 
placed under the shoulders, the head being kept in a line with the trunk. The tongue 
should be drawn forward, so as to project a little from the side of the mouth ; then the 
arms should be drawn upward until they nearly meet above the head, the operator grasp- 
ing them just above the elbows, and then at onca lowered aad replaced at the side. This 



CAEE OF THE SICK AND EMERGENT CASES. 341 

should be immediately followed by moderate pressure with both hands upon the lower 
part of the sternum. This process is to be repeated about twelve or fourteen times in 
the minute. 

(2.) As soon as natural respiratory movements recommence, cease the employment of 
artificial means, unless the efforts are feeble and imperfect. Should no natural respira- 
tion supervene, a dash of hot water (120° F.) or cold water may be used. 

(3.) Maintain the temperature of the body by friction, warm blankets, and, when pos- 
sible, by warm water (106° F.) or air-bath, keeping the head where a circulation of pure 
air may be maintained. 

(4 ) As soon as the patient can swallow, give warm milk, beef tea, tea, or coffee, with 
a tablespoonful of some spirit, or these may be injected by the stomach-pump. 

(5.) When respiration is restored, put the patient into a warm bed, with hot bottles to 
his feet, and encourage sleep; but let him be watched, in case of secondary or relapsing 
apnoea, at the slightest symptom of which let friction and even artificial respiration 
be employed. Give volatile stimulants, such as spiritus ammonise aromaticus {Bryant). 

559. Dr. Voisin, of Paris, reports the absolute certainty of restoring to life persons who 
have remained under water from a few seconds to five minutes. These results have 
been attained at Paris in cases of water-drowning accompanied by asphyxia, as well as 
by syncope. He ascribes them to the vigorous carrying out of the Silvester method ; 
to the application of warmth by heaters to the entire surface of the body ; to the use 
of warm baths and cold douches ; to keeping the patient quiet in bed for some hours 
after restoration ; and to the efforts of a trained and disciplined staff. 

560. Prevention fhom Drowning. — In the water the human 
body weighs about a pound. When it is a question of life or 
death, do not attempt to raise your body out of the water. One or 
both hands placed on a block of wood, a stool, or a chair will enable 
a person to keep the mouth and nose out of the water. This is all 
that is of vital importance until aid arrives. All persons should 
be trained, when in the water, to know and to have faith in its 
buoyant powers. In case of a wreck, know that an overturned or 
water-filled wooden boat will sustain more persons in the water 
than it will carry. Do not permit any one to climb on it, for that 
will jeopardize the safety of all hanging on to the wrecked boat. 

561. Bodies in the External Ear. — The sooner a foreign 
body is out of the external auditory meatus the better. To remove 
wax, introduce a few drops of glycerin and water into the meatus for 
two or three nights ; then, with an ear-syringe, direct a stream of 
tepid water into the meatus obliquely against the walls, and thus the 
water will get behind the wax and wash it out. To direct the stream 
against the wax does but little good, and to direct it against the mem- 
brana tympani does positive injury. To remove peas, beans, beads, 
etc., is often a work of difficulty, for the outer third of the meatus 
is wide, the middle third contracted, and the inner third enlarged. 
(See Fig. 94.) The passage, having bony walls, cannot be expanded. 

29^- 



342 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

If vegetable or animal materials remain, by the absorption of water 
they expand, and thus render their removal more ditficult. Some- 
times the body can be washed out by getting water back of the ob- 
ject. In other cases it may be floated out by filling the meatus 
with warm oil. If these fail, make a loop of twisted iron wire, in- 
troduce it into the ear, against one of the sides of the passage, 
turn it half around, noose the body, and jerk it out. If an insect 
or worm enters the meatus, fill the passage with warm oil, and the 
intruder will leave. 

562. Bodies on the Surface of the Eyeball. — When for- 
eign bodies, as dust, cinders, etc., lodge upon the surface of the ball, 
or beneath the lids, do not rub the part. Hold the lids open, while 
the eye is rolled either up and down or from side to side. In this 
way the fragment may be removed. If not, hold up the upper lid 
and blow the nose; if this fails, seize the lashes of the upper lid 
and draw it away from the eye, then look down, and push the lower 
lid beneath the upper, and thus the lashes may brush out the body. 
If this is ineffectual, place a small pencil under the eyebrow, and 
quickly, by aid of the eyelashes, turn the upper lid over the pencil. 
Kemove the offending body, if possible, with the corner of a moist- 
ened handkerchief. If this fails, summon a surgeon to remover the 
body. After the removal of the body, drop into the eye a drop of 
castor oil. This will ease the gritty sensation which persists after 
the removal of the foreign material. 

563. Frost-Bite. — Frost-bite is usually manifested first upon 
parts unprotected by covering, as the face or ears, and especially 
the nose. In such case the skin first becomes red, fi:om congestion 
of the dilated capillary vessels ; next it becomes bluish, from arrest 
of the circulation, and afterwards of a dead-white hue. To restore 
circulation and sensibility, rub the frozen part with snow, or apply 
iced water. Keep the sufferer at first in a cold room, and let the 
return to a higher temperature be gradMol and cautious, else gan- 
grene may supervene. 

564. Hernia, or Kupture. — A person who has hernia should 
never be allowed to become constipated (164). If the hernia comes 
down and cannot be replaced, place the sufferer on a bed. Apply 
ice in a rubber bag, or ice rolled in a single layer of flannel, over 
and about the parts. Wait an hour. Give the patient a Dover's 
powder. Place one or two pillows under the shoulders, flex the 



CAEE OF THE SICK AND EMERGENT CASES. 343 

thighs on the abdomen, raise the swelling, and endeavor by gentle 
manipulations to cause the parts last out to return first. If this 
does not succeed, place the patient with his abdomen resting on 
the back and his limbs over the shoulders of a strong man. Then 
let the man slowly rise. By this manoeuvre, gravity tends to pull the 
escaped contents back into the abdomen. If this fails, send at once 
for the ablest surgeon in the vicinity. The danger following in the 
course of strangulated hernial contents cannot be overestimated. 

565. Retention of Urine. — Place the sufferer in a hot bath, or 
employ the Simpson bath (47). Administer two Dover's powders, 
or two grains of opium. Usually micturition will soon be induced. 
If not, after half an hour in the bath, remove the patient to a warm 
bed. Apply over the pubis cloths wrung out of hot water upon 
which camphor has been sprinkled. Send for a surgeon. 

566. Simpson's Bath. See 1[ 47, Chapter III. 

567. Wounds. — Wounds punctured by the human teeth, by dogs 
and cats ; from rusty nails, thorns, etc. As the deep parts so injured 
cannot be reached in order to be cleansed, apply over and about 
the entrance a poultice of bread, or of linseed or corn meal (544). 
Change once in four to six hours. This treatment favors the for- 
mation of pus, hinders healing at the surface, and tends to draw the 
foreign materials from the base of the wound. 

Wounds from Suspected Mad Dogs or Mad Cats [Babies). — Cau- 
terize at once freely with lunar caustic (nitrate of silver), or pour 
into the wound a strong acid or alkali. Do not kill the dog or 
cat. Keep it in confinement, and thus ascertain if it is really mad. 
By this means much mental anxiety may be avoided. Mental 
stimulants must be freely administered, and the person's mind 
diverted. 

Wounds from Poisonous Serpents. — Give whiskey, brandy, or rum 
freely. Apply at once ligatures, or tight cords, around the parts, 
between the wound and the heart. Tie them very tight. Cut open 
the wound, to favor bleeding. Suck the wound: if you have no 
sore in the mouth, you run no risks. Then apply caustics or a live 
coal. The patient may drink from one to three pints of whiskey or 
brandy. The man dying from snake-bite perishes from rapid ex- 
haustion of nerve-force : hence stinuilate. If water of ammonia is 
at hand, add four or six teaspooniiils to each pint of liquor. Sus- 
tain the powers by nourishing food, like milk and eggs. 



344 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Woiaids from Insects. — Apply cooking-soda made into a paste. 
Strong water of ammonia is, however, more efficacious. Olive oil 
often makes an excellent application. If these are not at hand, 
cover the bitten part with flour paste. 

568. Irritation from Ivy-Poison (Ehus). — Apply constantly to 
loose cloths placed over the parts a lotion composed of carbolic 
acid, one part ; sulphite of soda, six parts ; and spring-water, sev- 
enty parts. 

569. Sunstroke. — "More properly Heat-stroke, because it takes 
place on cloudy days and under any circumstances of exposure to 
great heat in a debilitated condition of the body, arising from over- 
exertion or frequently from intemperate habits. A large green leaf 
worn in the hat, or a moist light handkerchief, very certainly pre- 
vents sunstroke. Symptoms: The person falls suddenly, as in a 
common fainting-fit, but the head is very hot ; so, at once take the 
patient to the shade, and pour a continuous stream of cold water 
on the head, crosswise, in every direction, so as not to fall on one 
spot. Mustard plasters may be applied to the spine and stomach 
alternately. The Egyptians pour salt water over the head and 



GLOSSAEY. 



THE NUMEKALS DIRECT ATTENTION TO THE NUMBERED PARAGRAPHS. 
TO WHICH THE STUDENT IS ADVISED TO REFER. 



Ab-do'men. (246.) [L. abdo, to hide.] 
That part of the body which lies be- 
tween the thorax and the bottom of the 
pelvis. 

Ab-dom'i-nal. Pertaining to the abdomen. 

Ab-du'cens. [L. ab, from, and duco, to 
lead.] Drawing to a different point. 
The nerve of the rectus externus of the 
eyeball. 

Ab-duc'tor. [L. abduco, to lead away.] 
A muscle which moves certain parts by 
separating them from the axis of the 
body. 

Ab-lu'tion. The act of washing. 

Ab-nor'mal. [L. ab, from, and norma, 
a rule.] Contrary to the general order. 

Ab-sorp'tion. (276.) [L. ab, and sorbere, 
to suck up.] The process of taking into 
a vessel or into the system. 

Ac-com-mo-da'tion. (458.) The act of 
fitting or adapting, as in vision. 

Ac-e-tab'u-Ium. [L. acetwm, vinegar.] 
The socket for the head of the thigh- 
bone, — so oalled from its resemblance to 
an ancient vessel for holding vinegar. 

A-chil'lis. A term applied to the tendon 
of the two large muscles of tlie leg. 

A-cro'mi-on. [Or. oZtos, highest, and 
<mus, the shoulder.] A process of the 
scaiiula that joins to the clavicle. 

Ad-duc'tor. [L. abduco, to lead to.] A 
muscle which draws one part of the 
body towards another :— opposed to ab- 
ductor. 

Ad'e-noid. (2!)4.) [Or. adcii, a gland.] 
Tissue resembling gland tissue. 

Ad'i-pose. (25.) [L. adeps, fat.] Relating 
to fat. 



A-e-ra'tion. [Gr. aer, air.] The act of 
supplying with air. 

Affe-rent. (81.) [L. ad, and /ero, I carry.] 
Conveying inward, as from the skin to 
the spinal cord. 

Air'-Space. (203.) Cubic space allowed 
men or animals in habitations. 

Al-bi'no. (452.) [L. albus, white.] An 
individual of any race of men having 
white hair and skin and a peculiar red- 
ness of the pupil of the eye. 

Al-bu'men. (217.) [L. aZbws, white.] The 
chief constituent of the white of egg. 

Al-bu'mi-noids. (217.) A class of prin- 
ciples resembling albumen. 

Al'co-hol-ism. (408.) A series of dis- 
eased activities produced by the use of 
alcoholics. 

Al'i-ment. (216.) [L. alere, to nourish.] 
Food ; nutriment. 

Al-i-ment'a-ry Ca-nal'. (249.) The mus- 
culo-membi-anous tube into which nu- 
triment is taken to be digested, and by 
which it is conveyed tlirough the body, 
the useless parts to be evacuated. 

Al-ve'o-lar. [L. alveolus, a socket.] Per- 
taining to the sockets of the teeth. 

Am-bly-o'pi-a. [Gr. aiublun, obscure, and 
ops, the eye.] linpairniont of vision ; 
weakness of vision. 

A-moe'ba. See1|6. 

A-moe'boid. [Gr. anicibo, T change, and 
cidos, resemblance.] A term applied to 
spontaneovis changes of sliape and posi- 
tion in cells. 

Am-mo'ni-as. (412.) Compounds contain- 
ing ammonia (NH3) or derivatives of 
ammonia. 

345 



346 



GLOSSARY. 



Am'pli-tude. Largeness; the degree of 
motion. • 

Am-pul'la. A dilatation ; an enlargement 
at one end of the semicircular canals of 
the ear. 

An-aes-the'si-a. [Gr. an, against, and 
aisthanomai, I feel.] The absence of sen- 
sation, especially of touch. 

A-nas'to-mose. (105.) [Gr. ana, through, 
and stoma, a mouth.J To unite as vessels 
or branches ; to inosculate with one an- 
other. 

An-a-tom'i-cal. Relating to the parts of 
the body when dissected or separated. 

A-nat'o-my. [Gr. ana, through, and tome, 
a cutting.] The description of the 
structure of animals. (The word anatomy 
properly signifies dissection.) 

An'gu-li. [L. auguhis, a corner.] A term 
applied to certain muscles on account of 
their form. 

An'nu-lar. [L. annulus, a ring.] Having 
the form of a ring. 

An-tag-o-nis'tic. An agent producing 
an effect contrary to that of another 
agent. 

An-te'ri-or, [L. ante, before.] Situated 
before the median line : — opposed to pos- 
terior. 

An'te-ro-Lat'e-ral. Pertaining to front 
and side. 

An'te-ro-Pos-te'ri-or. From front to rear. 

An'thro-poids. [Gr. anthropos, man, and 
eidos, form.] The name given to the man- 
like apes, — gorilla, chimpanzee, ourang, 
and gibbon. 

An-ti-scor-bu'tic. (225-233.) [Gr. anti, 
against, and scorbutus, scurvy.] A sub- 
stance or influence which prevents or 
mitigates scurvy. 

An'trum. [L., a cave.] A cavity in the 
superior maxillary bone, the entrance to 
which is smaller than the bottom. 

A-or'ta. (99.) [Gr. aorte; from aer, the 
air, and tereo, to keep.] The great artery 
that arises from the left ventricle of the 
heart. 

Ap'er-tures. Mouths or openings. 

A'pex. The point or extremity of a part, 
as of the heart. 

A-pha'si-a. (358.) [Gr. «, without, and 
phemi, to say.] Speechlessness. 



Ap-noe'a. (188.) [Gr. a, without, and 
pneo, I respire.] Absence of respiratory 
movements. 

A-po-neu-ro'sis, [Gr. apo, from, and 
neuron, a nerve.] The membranous ex- 
pansion over muscles and tendons. The 
ancients called every white tendon neu- 
ron, a nerve. 

Ap-pa-ra'tus. [L. apparo, to prepare.] 
An assemblage of organs designed to 
produce certain results. 

Ap-pend'a-ges. [L. ad, and pendeo, to 
hang from.] Something connected to 
a part. 

Ap-pen'dix. [L. ad, and pendeo, to hang 
from.] Something appended or added. 

Ap-po-si'tion. (340.) Accurate contact ; 
a setting to. 

A'que-ous. [L. aqua, water.] Pertaining 
to or like water. 

A-rach'noid. (367.) [Gr. arachne, a spider, 
and eidos, form.] Resembling a spider's 
web. 

Ar'bor. [L.] A tree. Arbor Vitse, the tree 
of life, — a term applied to a part of the 
cerebellum. 

A're-as. The spaces or portions of an 
organ or system. 

A-re'o-lar. (22.) [L. area, a void place, 
an open surface.] Pertaining to the in- 
terstices between the fibres composing 
organs. 

Ar'gand. The burner invented by Ar- 
gand, of Geneva, in 1782. 

Ar'rack. An intoxicant made from the 
palm and rice by the East Indians. 

Ar'te-ry. (105.) [Gr. aer, air, and tereo, 
to keep; because the ancients thought 
that the arteries contained only air.] A 
tube through which blood flows. 

Ar-tic-u-la'tion. (506.) [L. ar^»<s, a joint.] 
The union of bones with each other. 
Also, the forming of syllables by the or- 
gans of speech. See Voice (492). 

A-ryt'e-noid. (488.) [Gr. arMtawia, a ewer, 
and eidos, form.] The name of a carti- 
lage of the larynx. 

As-cen'dens. [L.] Ascending; rising. 

As-phyx'i-a, [Gr. a, without, and sphyxia, 
pulse.] Originally, want of pulse ; now 
used for suspended respiration, or ap- 
parent death. 



GLOSSARY. 



347 



As-sim-i-la'tion. (307.) The process of 
making food-stuffs like the components 
of the organs and tissues. 

As-so-ci-a'tion. Union of activities for a 
given purpose. 

As-the-no'pi-a. (485.) [Gr.asthenis,-wea.k, 
and ops, the eye.] Weakness of sight. 

A-stig'ma-tism. (461.) [Gr. a, without, 
and stigma, a point.] Irregular refrac- 
tion of the eye, producing a blurred 



At'ro-phied. [Gr. «, without, and trophe, 
nourishment.] Diminution in bulk of a 
part. 

A-tro'pi-a. (452.) The active principle of 
Atrojia Belladonna, or deadly night-shade. 

Au-di'tion. [L. audio, to hear.] Hearing. 

Au'di-to-ry. (439.) Pertaining to the 
sense or organ of hearing. 

Au'ri-cle. [L. auricida, the external ear; 
from auris, the ear.] A cavity of the 
heart. 

Au-to-mat'ic. Acting of itself :— applied 
to an action of a body, the causes of 
which appear to lie in the body itself. 

Au-tom'a-tism. See f 84. 

Ax-il'la. [L.] The armpit. 

Ax'il-la-ry. Belonging or relating to the 
armpit. 

Az'ote. [Gr. a, without, and zoe, life.] 
Nitrogen, — one of the constituent ele- 
ments of the atmosphere : so named be- 
cause it will not sustain life. 



Band' -Ax-is. (78.) The central portion of 
the nerve-fibre. 

Bane'ful. Having poisonous qualities. 

Bar'y-tone. [Gr. hams, heavy, and tonos, 
tone.] A male voice whose compass is 
between that of the tenor and the base. 

Base of Skull. The foundation or sup- 
port of the brain. 

Bath. (47.) The immersion of the whole 
or a part of the body in some medium, 
as water, mud, or sand. 

Bi'ceps. [L. hi^, twice, and caput, a head.] 
A name applied to muscles with two 
heads at one extremity. 

Bi-cus'pids. (254.) [L. his, two, and cusins, 
a point.] Teeth that have two points 
upon their crown. Tremolars. 



Bi-lat'er-al. [L. hi, and lateralis, pertain- 
ing to the side.] Referring to two sides. 
Bi-noc'u-lar. (466.) [L. his, two, and 

oculis, eye.] Relating to both eyes. 
Bi'o-plasm. (9.) [Gr. bios, life, and plasso, 

to form.] The physical-basis of life. 
Bi-pen'ni-form. [L. his, two, and penna, 

a feather.] Having fibres on each side 

of a common tendon. 
Blis'ter. (28.) A collection of serous fluid 

under the epidermis. 
Bolt'ed. (285.) Insufficiently masticated 

and insalivated food hastily swallowed. 
Brach'i-al. [L. hraddum.] Belonging to 

the arm. 
Bre'vis, Bre'vi-or. [L.] Short. Shorter. 
Bron'chi-a, pi. Bron'chi-se. (163.) [L.] 

A division of the trachea that passes to 

the lungs. 
Bron-chi'tis, [L.] An inflammation of 

the bronchial mucous membrane. 
Buc-ci-na'tor. [L. huccinum, a trumpet.] 

The name of a muscle of the cheek:— - 

so called because used in blowing wind 

instruments. 
Buoy'an-cy. The quality of floating, as 

on water. 
Bur'sae Mu-co'sse. [L. bursa, a purse, and 

mucosa, viscous.] 'Small sacs, containing 

a viscid fluid, situated about the joints, 

under tendons. 
Bu-tyr'ic Ac'id. (219.) The name of an 

acid obtained from butter. 

C. The chemical symbol of carbon. 

Ca. The chemical symbol of calcium, the 

base of calx or lime. 
Cse'cum. [L. blind.] The name given to 

the commencement of the colon. 
Cal'cis. [L.] The hoel-bone. 
Cal'ci-um. [L-] The metallic basis of lime. 
Cal'i-bre. The diameter of a tube. 
Cal-is-then'ics. [Gr. kalos, beautiful, and 

stheiios, strength.] Exercises pursuoil fov 

the development of ease and bounty ol' 

motion. 
Cal'lus. (311.) Unnatural thickness and 

luudness of the outer skii\. 
Ca-lor'ic. (189.) [L. calor, heat.] The 

agent inducing the sensation of heat. 
Cam'e-ra. [L., a chamber.] The dark box 

used in photography. 



348 



GLOSSARY. 



Can-a-lic'u-lus, pi Can-a-lic'u-li. (505.) 

[L. canalis.] A small channel. 

Can'cel-la-ted. (501.) IL.caucelU.] Hav- 
ing a latticed appearance. 

Ca'nine. (254.) [L. canis, a dog.] Per- 
taining to a dog, as dog-teeth, eye-teeth. 

Can'thus. [Gr. Jcanthos.] The angle formed 
by the junction of the eyelids. 

Cap'il-la-ry. [L. capillus, a hair.] Re- 
sembling a hair ; a small tube. 

Cap'sule. (45G.) [L. co^js^Za, a little chest.] 
A membranous bag enclosing a part. 

Ca'put. [L.] The head. Caput coli, the 
head of the colon. 

Car'bo-Hy'drates. (220.) Compounds made 
up of C, H, 0, like starch, sugar, etc. 

Car'bon. [L. carho, a coal.] Pure char- 
coal. An elementary combustible sub- 
stance. 

Car'bon Com'pounds. Chemical com- 
pounds whose base is carbon. 

Car-bon'ic Ay'id, A gas produced by per- 
fect combustion of carbon in oxygen. 

Car-bon'ic Ox'ide. (195.) A colorless gas 
formed under imperfect combustion. 

Car'di-ac. (68.) [Gr. Tcarclia, the heart.] 
Relating to the heart, or to the upper 
entrance of the stomach. 

Car'ne-a, pi. Car'ne-ae. [L. caro, carnis, 
flesh.] Fleshy. 

Ca-rot'id. [Gr. haros, lethargy.] The great 
arteries of the neck that convey blood to 
the head. The ancients supposed drowsi- 
ness to be seated in these arteries. 

Car'pus, pi. Car'pi. [L.] The wrist. 

Car'ti-lage. (503.) A pearly-white, glis- 
tening, elastic substance found adherent 
to bones. 

Car'un-cle. [L. euro, flesh.] The small 
red body at the inner angle of the eye. 

Ca'se-in. (217.) [L. caseiis, cheese.] The 
principal nitrogenous portion of milk. 
The constituent of cheese. 

Cat'a-lep-sy. [Gr. Jcalalamhano, to seize.] 
A total suspension of sensibility and 
voluntary motion ; a trance. 
Cat'a-ract. [Gr. katarrasso, to fall down.] 
Obstructed vision, due to disease^ of the 
crystalline lens or its capsules. 
Ca-tarrh'. [Gr. ^-atoreo, to flow down.] A 
profuse secretion from a mucous surface, 
as in a cold. 



Cau-ca'si-an. One of the races of men. 
Ca'va. [L.] Hollow. Vena cava, 

given to the two great veins of the body. 
Cell. (8.) The anatomical unit.; 
Cell-Body. (8.) The central mass of pro- 
toplasm. 
Cel'lu-lar. [L. cellula, a little cell.] Com- 
posed of cells. See Areolar. 

Cel'lu-lose. (221.) The chief component 
of plants. 

Ce-men'tum. (201.) A portion of the 
outer layer of the teeth. 

Cen-tim'e-tre. The hundredth part of a 
metre, or 0.394 of an English inch. 

Cer-e-bel'lum,jj/.Cer-e-bel'la. (363.) [L.] 
The hinder and lower part of the brain, 
or the little brain. 

Cer'e-bral. [L. cerebrum, the brain.] Be- 
longing to the brain. 

Cer-e-bra'tion. The action of the brain 
during mental or moral manifestation. 

Cer'e-bro-Spi'nal. Relating to the brain 
and spine. 

Cer'e-brum. (352.) [L.] The front and 
large part of the brain. The term is 
sometimes applied to the whole contents 
of the cranium. 

Cer'vi-cal. Relating to the neck. 

Cer'vix. [L.] The neck. 

Chem'is-try. (1.) The science of the 
statics and dynamics of atoms. 

Chest. [Sax.] The thorax; the portion 
of the body from the neck to the dia- 
phragm. 

Chlo'ral. (409.) [Chlor, from chlorine, 
and «7, from alcohol.] Prepared by the 
action of chlorine on alcohol. A hyp- 
notic. 

Chlo'ral-ism. (409.) The condition re- 
sulting from using chloral. 

Chlo'rine. [Gr. chloros, green.] A gas, so 
named from its color. 

Chon'drin, (216.) [Gr. cJiondros, cartilage.] 
Gelatin obtained from cartilage : — a pro- 
teid. 

Chor'da, pi. Chor'dae. [L.] A cord. An 
assemblage of fibres. 

Chor'dae Ten-din'e-ae. (97.) The tendon- 
like cords found in the interior of the 
heart. 

Cho-roi'de-a. (451.) [Gr. chorion, skin.] 
The second tunic of the eyeball. 



GLOSSARY. 



349 



Chro-mat'ic Ab-er-ra'tion. (461.) [Gr. 
chroma, color, and L. ab, from, and erro, 
to wander. ] Irregular refraction of color- 
rays. 

Chyle. (278.) [Gr. chulos, juice. J A nu- 
tritive fluid, of a whitish appearance, 
which is made from food by the action 
of the digestive organs. 

Chyl-i-fi-ca'tion. [L. chylus, chyle, and 
facio, to make.] The process by which 
chyle is formed. 

Chy-lo-poi-et'ic. [Gr. chulos, juice, and 
;poieo, to make.] Connected with the 
formation of chyle. 

Chyme. (276.) [Gr. chumos, juice.] A 
kind of grayish pulp formed from the 
food in the stomach. 

Ci-ca'trix. (32.) [L.] The scar of a healed 
wound. 

Cil'i-a. [L., plural of cilium.] Eyelashes, 

Cil'i-a-ted. (68.) [L. cilia, eyelashes.] 
Having hair-like projections. 

Cin-e-ri'tious. [L. cinis, ashes.] Having 
the color of ashes. 

Cir-cu-la'tion. (124.) [L. circuhdio, a 
going round.] The name given to the 
motion of the blood through the different 
vessels of the body. 

CI. The chemical symbol of the element 
chlorine. 

Clav'i-cle. [L. clavicula, from clavi^, a 
key.] The collar-bone : — so called from 
its resemblance in shape to an ancient 
key. 

Clei'do. A term applied to some muscles 
that are attached to the clavicle. 

Clot. (122.) [Dut. klnit, a mass or lump.] 
Soft or fluid matter becoming thicker or 
more solid, as a concretion of stagnant 
blood. 

Co-ag-u-la'tion. (120.) [L. coiKjnlo, to 
curdle.] The process of producing a 
thickened state in albuminoid fluids. 

Co-ag:'u-lum. [L.] A coagulated or cur- 
dled substance. 

Coc'cyx. [Gr.] An assemblage of small 
bones attached to the sacrum. 

Coch'le-a. [Gr. kochlo, to twist; or L. 
cochlea, a screw.] A cavity of the ear 
resembling in form a snail-slu»ll. 

Coe'li-ac. [Gr.A()i7((t, the belly.] Belonging 
to the belly. 



Col'ic. Acute pain in the abdomen, ag- 
gravated at intervals. 

Col'loid. [Gr. kolla, glue, and eidos, form.] 
Resembling glue. 

Co'lon. [Gr. kolon, curtailed.] A portion 
of the large intestine. 

Col'or-Blind'ness. (464.) Daltonism. 

Com-bus'tion. (181.) [L. combustio, a burn- 
ing.] Burning. The chemical union of 
oxygen with other elements or com- 
pounds. 

Com-mis'sure. (450.) [L. con, together, 
and mitto, missum, to put.] A point of 
union. 

Com-mu'nis. [L.] A term applied to 
certain muscles working together. 

Com-plex'us. [L. complector, to embrace.] 
The name of a muscle that embraces 
many attachments. 

Com-press'or. [L. con, together, and 
premei-e, pressum, to press.] A term ap- 
plied to some muscles that compress the 
parts to which they are attached. 

Con'di-ments. (224.) [L. condire, conditum, 
to season.] Substances taken with food to 
improve flavor or to promote digestion. 

Con-duo' tion. The passage of heat or 
electricity from one particle to another. 

Con'dyle. [Gr. kondidos, a knuckle, a pro- 
tuboi'ance.] A prominence on the end 
of a bone. 

Con-junc-ti'va. (448.) [L. con, together, 
and jiuigo, to join.) The membrane that 
covers the front of the eyeball. 

Con'so-nants. (496.) Letters which can- 
not be perfectly sounded without the aid 
of a vowel. 

Con'stant Cur' rent. The electric current 
developed from direct chemical action. 
Voltaic electricity. 

Con-sti-tu'tion. [L. con, together, and 
statito, to sot.] The particular fi-ame or 
teniiH'ianu'ut uf the human body. 

Con-sump' tion. (208, ) [L. coiisuduk to 
waste away.] A wasting away of tlu- 
tissues. Usually applied to phthisis of 
the lungs. 

Con-ta'gion. (200.') [L. con. with, and 
tamjo or /<(;/<>, to touch.] The conununi- 
cation of disease by contact or the in- 
halation of the etlluvia of a sick per- 
son. 



30 



350 



GLOSSARY. 



Con-trac'tile. (77.) [L. con, together, and 
traho. tractum, to draw.] Possessing con- 
tractility. 

Con-trac'tion. The shortening of living 
fibre on the application of stimulus. 

Con-va-les'cent. [L. convalesco, to grow 
strong.] Eecovering health after disease. 

Con' vex. Swelling on the exterior surface 
into a round or spherical form. 

Con-vo-lu'tion. (352.) [L. con, together, 
and volvo, volutum, to roll.] The tortuous 
eminences of the cerebrum. The irregu- 
lar twistings of the intestines. 

Con-vul'sion. [L. convello, to pull to- 
gether.] Yiolent agitation of the limbs 
or body. 

Co-or-di-na'tion. See ^ 393. 

Cor'a-coid. [Gr. korax, a crow, and eidos, 
form.] A process of the scapula shaped 
like the beak of a crow. 

Co'ri-um. (28.) [Gr. chorion, the skin.] 
The true skin. 

Corn. (31.) [L. conn;, a horn.] A horny 
hardness of the epidermis. 

Cor'ne-a. (451.) [L. cornu, a horn.] The 
transparent membrane in the fore part 
of the eye. 

Cor'o-na-ry. [L. corona, a crown.] Ap- 
plied to vessels, nerves, etc., which en- 
circle parts. 

Cor'po-ra. [L., plural of corpus, a body.] 
The name given to eminences or projec- 
tions found in the brain and some other 
parts of the body. 

Cor'po-ra ftuad-ri-gem'i-na. (353.) [L.] 
The four oval-shaped bodies of the base 
of the brain. 

Cor'pus Cal-lo'sum. (352.) [L., the hard 
body.] The white bond of union of the 
cerebral hemispheres. 

Cor'pus-cle. [Dim. of L. corpus, a body.] A 
small body, as a_ blood-disk. 

Cos-met'ics. (40.) [Gr. cosmeo, to adorn.] 
Medicines supposed to beautify and im- 
prove the complexion. 

Cos'tal. [L. costa, a rib.] Eelating to the 
ribs. 

Cramp. Spasmodic contraction of the 
muscles independent of the will. 

Crep-i-ta'tion. [L. crepito, to crackle.] The 
sound caused by pressing cellular tissue 
containing air. A small crackling noise. 



Crib'ri-form. [L. crihrum, a sieve, and 
forma, form.] A plate of the ethmoid 
bone, through which the olfactory nerves 
pass to the nostril. 

Cri'coid. (488.) [Gr. kriA-os, a ring, and 
eidos, form.] A name given to a cartilage 
of the larynx, from its form. 

Crys'tal-line. (454.) [L. cri/skdlinus.] The 
crystalline lens, one of the media of the 
eye. It is convex, white, firm, and trans- 
parent. 

Cu'bi-tus, pi Cu'bi-ti. [L. cubitus, the 
elbow.] One of the bones of the fore- 
arm : — also called the idna. 
j Cu'boid. [Gr. kubos, a cube, and eidos, 
form.] Having nearly the form of a 
cube. 

Cu'mu-la-tive. A tenn applied to the vio- 
lent action from drugs which supervenes 
after the taking of several doses with 
little or no effect. 

Cu-ne'i-form. [L. cuneus, a wedge.] The 
name of bones in the wrist and foot. 

Cus'pid. (254.) [L. cuspis, a point.] Hav- 
ing one point : — applied to a tooth. 

Cu-ta'ne-ous. [L. cutis, the skin.] Belong- 
ing to the skin. 

Cu'ti-cle. (39.) [L. cidis.] The external 
layer of the skin ; the epidermis. 

Cu'tis Ve'ra. (28.) [L. cutis, the skin, and 
rera, true.] The internal layer of the 
skin ; the true skin. 

Cys-ti-cer'cus. (232.) [Gr. Auts^is, a bladder, 
and kerkos, a tail.] The tailed bladder- 
worm : — one stage in the life of the tape- 
worm, or Tsenia. 

Dal'ton-ism. (464.) Color-blindness. 
Dan'druff. (43.) Pityriasis. An oil-gland 

disease : — particiilarly applied to the 

scurf at the roots of the hair of the head. 
De-coo' tion. [L. de, down, and coqiio, coc- 

tum, to boil.] A preparation made by 

boiling substances in water to extract 

their virtues. 
Dec-us-sa'tion. (365.) [L. decusso, to cross.] 

Union in the shape of an X or cross. 
De-gen-er-a'tion, [L. degenero, to be worse 

than one's ancestors.] A diseased change 

in the structure. 
Deg:-lu-ti'tion. (261) [L.deglutitio,to8V!ail- 

low down.] The act of swallowing. 



GLOSSARY. 



351 



De-lir'i-um. [L. dellro, to rave.] Wander- 
ing of the mind, as seen in fevers. 

De-lir'i-um Tre'mens. (408.) Trembling 
delirium ; " the horrors." 

Del'toid. [Gr. delta,— the Greek letter A, 
— and eidos, form.] The name of a 
muscle that resembles in form the Greek 
letter A. 

Den'tal. [L. dens, a tooth.] Pertaining to 
the teeth. 

Dep-o-si'tion. The act of throwing down, 
as of lime salts in cartilage. 

Der'mis. (28.) [L., from derma, the skin.] 
The skin. 

Der'moid. [Gr. derma, the skin, and eidos, 
form.] Resembling the skin. 

De-scen'dens. [L. de, down, and scando, to 
climb.] Descending, falling. 

Dex'trin. A gum-like substance derived 
from starch. 

Di-a-be'tes. (308.) [Gr. dia, through, and 
baitw, to go.] An abnormal and diseased 
flow of urine. 

Di'a-phrag-m. [Gr. diaphragma, a parti- 
tion.] The midriff,— a muscle separating 
the chest from the abdomen. 

Di-ar-rhoe'a. [Gr. diarrhea, to flow 
through.] A morbidly frequent evacu- 
ation of the intestines. 

Di-ar-thro'sis. [Gr. dia, through, and ar- 
ihron, a joint] An articulation which 
permits the bones to move freelj' on 
each other in every direction. 

Di-as'to-le. [Gr. diastello, to put asunder.] 
The dilatation of the heart when the 
blood enters it. 

Di-e-tet'ics. (333.) That part of medi- 
cine which relates to diet or food. 

Dif-fer-en-ti-a'tion. The production of 
diverse parts from a germ by a process 
of development. 

Dif-fu'sion. (176.) [L. dipuuio, diffnsnm, 
to spread.] The gradual mixing of gases 
or of fluids when in contact or separated 
by porous walls or divisions. 

Di-ges'tion. [L. dis, apart, and (jero, to 
bear.] The process of preparing fotuls 
in the alimentary canal for absorption 
into the blood-current. 

Dig-i-to'rum. [L. digitus, a finger.] .\ 
term applied to certain muscles of the 
extremities. 



Di-la'tor. A muscle which dilates certain 
parts. 

Dip-so-ma'ni-a. [Gr. dipsa, thirst, and 
mama, madness.] An insatiable desire 
for intoxicants. 

Dis-charg-e'. An increase of material from 
a part that secretes a fluid. 

Dis-in-te-gra'tion. The breaking up into 
parts. 

Dis'tal. (385.) [L. disto, to stand apart.] 
Applied to the farthest extremity of a 
part. 

Dis-tri-bu'tion. (385.) The parts to which 
a nerve or an artery is apportioned. 

Di-ur'nal. (321.) [L. dies, day.] During 
the day. 

Dor' sal. [L. dorsum, the back.] Pertain- 
ing to the back. 

Drop'sy. (22.) An abnormal collection of 
fluid in the areolar tissue. 

Duct. (250.) [L. duco, ductum, to lead.] 
A canal or tube. 

Du-o-de'num. (264.) [L. duodenus, of 
twelve fingers' breadth.] The first por- 
tion of the small intestine. 

Du'ra Ma'ter. (367.) [L. duriis, hard, and 
mater, mother.] The outer membrane 
of the brain. 

Dys'en-ter-y. [Gr. dus, bad, and enteria, 
intestines.] A discharge of blood and 
mucus from the intestines, attended with 
tenesmus. 

Dys-pep'si-a. (281.) [Gr. dus, bad, and 
pepto, to digest.) Indigestion, or dis- 
ordered state of the digestive organs. 

Dysp-noe'a. (188.) [Gr. dus, diflicult. and 
pueo, to breathe.] Labored or diflicult 
Inspiration. 

E-con'o-my. [Gr. oikos, a house, and uenio, 
to arrange.] The total of the arrange- 
ments necessary to the animal system. 

Effer-ent. (81.) [L. e//e>-o, to carry out.] 
C'ouveyiug from the central portions 
outward. 

Ef-flu'vi-a. [1/., from fjlluo, to flow out.] 
Exhalations or vapors coming from tlie 
body, and from decaying animal or vege- 
table substances. 

E-gres'ta. (3Ht.) [L., from egero, to ciwt 
out. ] The natural excretions, like urine, 
excrement, etc. 



352 



GLOSSARY. 



E-las-tic'i-ty. (69.) [Gr. elauno, to impel.] 
A property impelling a body of itself to 
return to its normal form. 

E-lim-i-na'tion. [L. e, out of, and Ibnen, 
a threshold.] Expulsion or discharge 
from an organ, a tissue, or the system. 

Em-a-na'tion. [L. emano, to issue from.] 
The miasm from putrid materials. 

Em'i-nen-ces. (362.) [L. e, out of, and 
miiieo, I project.] Projections on the 
surface of an organ. 

Em-me-trop'ic, (460.) [Gr. em, in, metron, 
a measure, and optomai, I see.] Pertain- 
ing to emmetropia, or the condition of 
the normal eye. 

E-mo'tion. [L. e, out of, and moveo, to 
move] Passion or delirium independ- 
ent of the will. 

Em-phy-se'ma. [Gr. emphusao, to inflate.] 
Collection of air in the areolar tissue 
under the skin, or in the interlobular 
lung-tissue. 

Em-py-reu-mat'ic. (230.) [Gr. empureno, 
to kindle.] Having the taste or smell 
of slightly-burnt animal and vegetable 
substances. 

E-mul'sion. (274.) Oil divided and held 
in a state of fine drops in a -n-ater con- 
taining an alkali or a mucilage. 

En-am'el. The smooth, hard substance 
which covers the crown or visible part 
of a tooth. 

En-ceph'a-lon. (350.) [Gt. eghepludon, the 
brain.] The contents of the skull ; the 
brain. 

En-do-car' di-um, (95.) [Gr. e;ifZo/i, within, 
and kardia, the heart.] The lining mem- 
brane of the heart. 

En'do-lymph. (440.) [Gr. endon, wittiin, 
and hjriipha, water.] The fluid in the in- 
ternal ear. 

End'-Or'gan. The outer terminal mecha- 
nism of a sensory nerve. 

En-dos-mo'sis. [Gr. endon, within, and 
osmos, impulse.] The transmission of 
fluids through membranes inward. 

En-er-va'tion. (402.) [L. enervo, to weak- 
en.] A weakened condition of the ner- 
vous system. 

En-tail'. (402.) [Fr. entaiUer, to cut deep.] 
A legacy transmitted from generation to 
generation. 



E-pen'dy-ma. [Gr.] The membrane which 
lines the ventricles of the brain. 

Ep-i-dem'ic. [Gr. epi, upon, and demos, the 
people.] An extensively prevalent dis- 
ease. 

Ep-i-der'mis. (28.) [Gr. epi, upon, and 
derma, the sldn.] The superficial layer 
of the skin ; the cuticle. 

Ep-i-glot'tis. (160.) [Gr. epi, upon, and 
glotta, the tongue.] A cartilage of the 
larynx, which covers the glottis during 
deglutition. 

Ep'i-lep-sy. [Gr. epUambano,to seize ujwn.] 
Sudden attacks of con\Tilsions, with deep 
sleep and mouth-frothing. 

Ep-i-the'li-um. (156.) [Gr. epi, upon, and 
thele, a nipple.] The upper cell layers 
of a mucous or serous membrane. 

E-qui-lib'ri-um, Sense of. See 1T»[ 372, 
474, and 475. 

Es-e-ri'na. (452.) The active principle 
of the Calabar bean, Physostigma. 

Eth'moid. [Gr. ethmos, a sieve, and eidos, 
form.] A bone of the skull. 

Eu-sta'chi-an Tube. A channel from the 
fauces to the middle ear, named from 
Eustachius, who first described it. 

Eu-tha-na'si-a. An easy death. 

Ex-ci'sion. [L. ex, out, and scindo, scissmn, 
to cut.] The cutting out of a part. 

Ex'cre-ment. [L. excerno, to separate.] 
Matter excreted and ejected; alvine dis- 
charges. 

Ex-cre'tion. (303.) [L. excerno, excretum, 
to sift out.] The process of separation 
of effete materials. 

Ex'cre-tive. (330.) A principle found in 
the excrement. 

Ex-ha'lant. [L. exhalo, to send forth va- 
por.] Having the quality of exhaling or 
forcing out air. 

Ex-pec-to-ra'tion. (195.) [L. ex, out, and 
pectus, the breast.] The act of ejecting 
from the air-passages mucus and other 
matters from the lungs by coughing, etc. 

Ex-pi-ra'tion. (174.) [L. expire, expiratum, 
to breathe forth.] The act of expelling 
air from the air-passages. 

Ex-ten' sion. [L. ex, out, and tendo, to 
stretch.] The act of restoring a limb 
to its natural position after it has been 
flexed or bent. 



GLOSSARY. 



353 



Ex-ten'sor. (514.) [L.] A term applied 
to a muscle that serves to extend any 
part of the body : — opposed to Flexor. 

Eye'-Piece. The portion of the compound 
microscope placed in the upper part of 
the tube. 

Fa'cial. [L. fades, the face.] Pertain- 
ing to the front and lower part of the 
head. 

Falx. [L. fulx, a scythe.] A process of the 
dura mater shaped like a scythe. 

Fa-rad'ic Cur'rent. The interrupted elec- 
tric current ; the electricity of induction. 

Fas'ci-a. (20.) [L. /ascts, a bundle.] The 
white fibrous expansion around muscles. 

Fas-cic'u-lus, pi Fas-cic'u-li. [L., dimin- 
utive of fuscis, a bundle.] A little bundle 
of muscular fibres. 

Fats. (219.) Vegetable and animal oils. 
They are mostly hydro-carbons. 

Fau'ces. [L.] The cavity at the back of 
the mouth. 

Fe. [L. ferrum, iron.] The chemical sym- 
bol of iron. 

Fem'o-ral. Pertaining to the femur. 

Fe'mur. [L.] The thigh-bone. 

Fe-nes'tra, pi Fe-nes'trse. (434.) [L.] A 
window : — a term applied to some open- 
ings in the internal ear. 

Fer-men-ta'tion. [L. fermento, to leaven.] 
The spontaneous changes which watery 
solutions or organic matter undergo 
under atmospheric influences. 

Fe'ver. (321.) A condition of the system 
characterized by continued elevation of 
the body-temperature, with disordered 
functions. 

Fi'bre. [L. fihra.] An organic filament 
or thread which enters into the compo- 
sition of animal and vegetable textures. 

Fi-bril'Ise. [L., diminutive ofjibm,] The 
microscopic filaments of muscular tis- 
sue. 

Fi'brin. (121, 217.) A protcid principle 
found in beyf, blood, and vegetal)les. It 
usually exists in the form of tough, 
elastic threads. 

Fi'bro-Car'ti-lag-e. An organic tissue par- 
taking of the nature of fibrous tissue 
and that of cartilage. 

Fi-brot'ic. Resembling fibrous tissue. 



Fib'u-la. [L., a clasp.] The outer and 
lesser bone of the leg. 

Fil'a-ment. [L. Jilamenta, thresids.] A fine 
thread. 

Fil'trate. That which has run through 
a strainer or filter. 

Fil-tra'tion. (227.) Straining. 

Fis'sure. (168.) [L._/indo,^ssM™, to cleave.] 
A deep groove or depression. 

Fl. The chemical symbol of fluorine. 

Flat'u-lence. (334.) [L. ^ah(s, wind.] A 
collection of gas in the stomach and in- 
testines. 

Flex'ion. [L. flectio.] The act of bending. 

Flex' or. (514.) [L.] A term applied to 
a muscle that flexes or bends a part. 

Flue. (201.) A tube or passage for air, 
cold or heated. 

Fol'li-cle. [L. follls, a bag.] A small se- 
creting cavity. 

Fo-ra'men, pi Fo-ram'i-na. [L., from 
foro, to bore a hole.] A small hole or 
opening. 

Fo-ra'men Mag'num. [L.] The great 
opening in the occipital bone at the base 
of the skull. 

Fore'arm. The part of the upper ex- 
tremity between the elbow and the 
hand. 

Fos'sa. [L , a ditch.] A cavity in a bone, 
with a large aperture. 

Fo've-a Cen-tra'lis. (462.) [L.] The cen- 
tral depression of the retina, in the yel- 
low spot. 

Frac'ture. IL. frango, fractiuu, to break.] 
The solution of continuity of a bono ; a 
break in a bone. 

Frse'num. [L., a bridle.] Frtviutm limjuir, 
the bridle of the tongue. 

Fron'tal. [L./Vohs, the forehead.] Belong- 
ing to the forehead. The bone of the 
forehead. 

Ful'crum. (514.) [L.] The fixed point 
about which a lever moves. 

Func'tion. [L. /(im/oc, to perform.] The 
appropriate action of an organ or system 
of organs. 

Fun'dus. [!'•] The bottom of anything, 
as of the eye or the bladder. 

Fun'gi-form. [ L. /»(((/((.< and ronfM.] Hav- 
ing torniinations like the head of a fun- 
gus or a mushroom. 

0* 



354 



GLOSSARY. 



Gan'grli-on, pi. Gan'grli-a. (84.) [Gr., a 
knot.] A collection of gray cells in the 
course of a nerve. 

Gan-gli-on'ic Sys'tem. (386.) A name 
given to the nervous system of organic 
life. 

Gas'tric. [G-r. gaster, the stomach.] Be- 
longing to the stomach. 

Gas'tro-Pul'mo-na-ry. (165.) Pertaining 
to lung and stomach regions. 

Gas-troc-ne'mi-us. [Gr. gaster, the stom- 
ach, and hieme, the leg.] The name of 
a large muscle of the leg. 

Gei'sha. A Japanese public dancer. 

Gel'a-tin. (216.) [L. gelo, to congeal.] A 
proteid substance derived from bone, 
cartilage, etc., by long boiling. 

Gen-er-a'tion. (399.) An age ; people 
living at the same time. 

Ging'ly-form. [Gr. ginglymos, a knife-like 
joint, and eidos, form.] An articulation 
that admits of motion in only two direc- 
tions; hinge-like. 

Gland. (250.) [L. glans, an acorn.] An 
organ whose function it is to secrete or 
separate some particular fluid from the 
blood. 

Gle'noid. [Gr. glene, a cavity.] A term 
applied to some cavities of bones. 

Glob'u-lin. (217.) A proteid constituent 
of the blood-corpuscles. 

Glos-sa. [Gr.] The tongue. Names com- 
pounded with this word are applied to 
muscles of the tongue. 

Glos-so-Pha-ryn'g:e-al. (382.) Kelating 
to the tongue and pharynx. 

Glot'tis. (489.) [Gr.] The narrow open- 
ing at the upper part of the larjmx. 

Glu'cose. (221.) [Gr. gr?i(Zros, sweet.] Grape- 
sugar. It may be obtained from starch 
by the action of acids, or of saliva. 

Glu-tse'us. [Gr.] A name given to mus- 
cles about the hip. 

Glu'ten. (217.) [L.] Glue. The residue 
after wheat flour has been deprived of 
starch. 

Glyp'e-rin. (219.) [Gr. glukos, sweet] A 
yellow, transparent, syrup-like fluid, the 
chemical base of animal fats. 

Gly'co-gren. (308.) [From glucose, and 
gennao, to produce.] A peculiar con- 
stituent of liver-tissue. 



Gom-pho'sis. [Gr. gomphos, a nail.] The 
immovable articulation of the teeth with 
the jaw-bone, like a nail in a board. 

Gout. (334.) Inflammation characterized 
by pain in the joints of the feet and 
hands. 

Gran'ule. [L. gmnum, a grain.] A mi- 
croscopic particle of matter. 

Grape Sugar. (221.) Glucose. 

Groin. The lower and lateral part of the 
abdomen. 

Gums. The red, firm, solid tissues which 
adhere to the necks of the teeth. 

Gus'ta-to-ry. (427.) [L. gusto, gustatum, to 
taste.] Belonging to the sense of taste. 

Gym-na'si-a. [Gr. gunmasion.] An estab- 
lishment for bodily exercise. 

H. The chemical symbol of hydrogen. 

Hae-mo-glo'bin. (180.) [Gr. haima, blood, 
and globus, a globe.] The iron compound 
of the red corpuscles. 

Hal-lu-ci-na'tion. (408.) [L. hallucinor, 
haUucbiatus, to mistake.] Mental error ; 
delusion. 

Ha'shish. (410.) A preparation of can- 
nabis Indica, or Indian hemp. 

Ha-ver'si-an. (505.) Pertaining to the 
canals of Havers found in bone-tissue. 

Hem-i-ple'gi-a. [Gr. hemisus, half, and 
plesso, to strike.] Paralysis affecting one 
side of the body. 

Hem'i-spheres. (352.) [Gr. hemi, half, 
and sphaim, a sphere.] The upper sphe- 
roidal portions of the brain, separated 
from each other by the falx cerebri. 

Hem'or-rhage. (122.) [Gr. haima, blood, 
and regmnni, to burst.] A discharge of 
blood from an artery. 

He-pat'ic. (270.) [Gr. hepar, hepatos, the 
liver.] Belonging to the liver. 

Herb'age. (202.) Grasses. 

He-red'i-ta-ry. [L. hssres, an heir.] 
Transmitted from parent to offspring. 

He-red'i-ty. The predisposition or tend- 
ency to definite x)hysiological actions de- 
rived from one's ancestors. 

Her'ni-a. [Gr. hernos, a branch.] A rup- 
ture or breach. A tumor arising from 
the protrusion of a portion of the intes- 
tines through an opening in the abdom- 
inal walls. 



GLOSSARY. 



355 



His-tol'o-gry. [Gr. 7<istos, tissue, and logos, 
discourse.] A description of the minute 
structures of the body. 

Hom-i-ci'dal. Murderous. 

Ho-mo-ge'ne-ous. [Gr. homos, equal, and 
genos, a kind.] Of the same kind or 
quality. 

Bo-mol'o-gous. [Gr. homos, same, and 
logos, relation.] Of the same essential 
nature. 

Hu'me-rus. [L.] The bone of the arm. 

Hy'a-loid. A transparent membrane of 
the eye. 

Hy'dro-Car'bons. (218.) Compounds of 
hydrogen and carbon. They include 
many of the group of fats and oils. 

Hy'dro-gen. [Gr. hudor, water, and gennao, 
to generate.] A gas which constitutes 
one of the elements of water. 

Hy-dro-pho'bi-a. [Gr. hudor, water, and 
phobeo, to fear.] A disease caused by the 
bite of a rabid animal ; rabies. 

Hy'gi-ene. (1.) [Gr. hugieinon, health.] 
The part of medicine which treats of 
the preservation of health. 

Hy'oid. (160.) [u, a Greek letter, and eicZos, 
form.] A bone resembling the Greek 
letter v in shape. 

Hy-per-aes-the'si-a. [Gr. hyper, excessive, 
and sesthesls, sensibility.] Diseased in- 
crease of sensibility. 

Hy-per-me-tro'pi-a. (460.) [Gr. huper, 
above, metrnn, a measure, and opis, vision.] 
" Flat eye :" — opposite to myopia, or near- 
sight. 

Hyp-not'ics. [Gr. htipnos, sleep.] Drugs 
having the power to induce sleep. 

Hy-po-chon-dri'a-cal. [Gr. hypo, under, 
and cltoiidros, a cartilage.] Having low 
spirits, a condition frequently connected 
with dyspepsia. 

Hy-po-der'mic. [Gr. /////«>, under, and 
(Icrnia, the skin.] A term used to denote 
the application of medicines under the 
skin. 

Hy-po-glos'sal. Undtn- tlie tongue. The 
name of a ncrv(> of the tongue. 

Hy-poth'e-sis. [V,r.] A supposition. A 
t!uH)ry is an accepted hypothesis. 

Hys-te'ri-a. A very complex morbid con- 
dition. It is probably a disonler of tlu> 
nervous system. 



I-de-a'tion. The action of the cerebrum 
in producing or evolving ideas. 

n'e-o-Cse'cal Valve. (268.) The mucous 
fold at the junction of ileum and caecum. 

Il'e-um. (264.) [Gr. eilo, to wind.] A 
portion of the small intestine. 

Il'i-ac, Pertaining to the haunch. 

Il'i-um. The outer expanded portion of 
the innominate bone ; the haunch-bone. 

Im'pulse. (349.) That which passes over 
the nerve fibres from nerve-cell group to 
nerve-cell group. 

In'cus. (433.) [L., an anvil.] The largest 
of the three bones of the internal ear. 

In'dex. [L. indlco, to show.] The fore- 
finger ; the pointing finger. 

In-di-vid'u-al. In zoology, the sum of 
the product of a single ovum or egg. 

In-duc'tion Shock. The sharp sensation 
induced by a sudden electric discharge 
from an induction coil. 

In-ert'ness. (197.) Tendency to inaction. 

In-flam-ma'tion. [L. inflammo, wflamma- 
tum, to set on fire.] A disordered func- 
tion, characterized by pain, heat, redness, 
and swelling. 

In-fu'sion. [L. in, upon, and fundo, fusum, 
to pour.] A solution of the soluble prin- 
ciples of a substance obtained by the ac- 
tion of warm or cold water. • 

In-hi-bi'tion. (85, 128.) [L. inhibeo, I hold 
in.] The stopping or checking of an 
already present action. 

In-ner-va'tion. (347.) The nervous in- 
fluence necessary for the maintenance 
of life and the functions of the various 
organs. 

In-nom-i-na'ta. (247.) [L. in, not, and 
iionieii, name.] Tarts which have uo 
proper name. 

In-os'cu-late. [Ij. ///, and itscnlntus, from 
osftdor, to kiss.] To unite, as two vessels 
at their extremities. 

In-sal-i-va'tion. i,-.">S.~) The process of 
mixing saliva witli food during masti- 
eati.m. 

In-ser'tion. ('A'A.) [li. insero, iuscrtHiii, to 
imiilant.] The utt^ichment of a muscle 
to a bone or other part. 

In-spi-ra'tion. (173.1 [L. in. in. and .<piro, 
spiraliiiii, to breathe.] The act of drawing 
iu the breath. 



356 



GLOSSARY. 



In-sta-bil'i-ty. [Chemical.] The tendencj' | 
of complex animal and vegetable com- 
pounds to split up readily into simpler 
chemical compounds. 

In-teg'u-ment. (20.) [L. intego, to cover.] 
The epidermis, rete, dermis, and sub- 
cutaneous areolar and fatty tissues taken 
together as forming a covering. 

In'ter. [L.] Between. 

In-ter-ar-tic'u-lar. (oil.) [L. inter, and 
articnlns, a joint.] Situated between the 
bones. 

In-ter-cel'lu-lar. (163.) [L. inter, and 
cellida, a little cell.] Between the cellu- 
lar spaces of tissues. 

In-ter-cos'tal. [L. inter, and costa, a rib.] 
Between the ribs. 

In-ter-mit'tent. (132.) [L. interrnitto, to 
leave off from time to time.] Intermis- 
sion. Irregularity of the interval of the 
beat of the heart. 

In-ter-no'di-i, [L. inter, between, and 
nodus, a knot.] A term applied to some 
muscles of the forearm. 

In'ter-stice. [L. inter, between, and sto, to 
stand.] The slight separation between 
organs or parts of organs. 

In-ter-ver'te-bral. Between the vertebrae. 

In-tes' tines. [L. intus, within.] The canal 
that extends from the stomach through 
the body, situated in the abdominal 
cavity. 

In-tox'i-cant. (242.) [L. in, in, and toxi- 
cnm, poison.] A substance which will 
induce drunkenness or inebriety. 

In-trin'sic. [L. intrinsems, on the inside.] 
"Within the organ or part. 

In-tus-sus-cep'tion. (10.) [L. ;«<!(«, within, 
and suscipio, snscepturn, to receive.] The 
taking of nourishment into the interior. 

In-vol'un-ta-ry. Independent of the will 
or power of choice. 

I'ris. (451.) [L., the rainbow.] The col- 
ored circle that surrounds the pupil of 
the eye. 

Ir'ri-ta-ble. (77.) Capable of responding 
to a stimulus. 

Ir-ri-ta'tion. (195.) [L. irrito, irritatum, 
to provoke.] Excessive action of an or- 
gan or tissue, causing a morbid increase 
of the circulation or disturbance of sen- 
sibility. 



Is'chi-utn. [Gr. ischion, the hip.] The 
portion of the innominata which serves 
as a support for the trunk when we are 
seated. 

I'vo-ry. A hard, solid, fine-grained sub- 
stance of a fine white color ; the tusk 
of an elephant. 

Je-ju'num. (264.) [L., empty.] A por- 
tion of the small intestine. 

Ju'gu-lar. [L. jngnhun, the neck.] Ke- 
lating to the throat or neck : — applied to 
the great veins of the neck. 

K. [L. kalium.] The chemical symbol of 

the element potassium. 
Kil'o-litre. One cubic metre, — about 

35.326 cubic feet. 
Kou'mis. An intoxicant made from the 

milk of the mare. The Tartars suck it 

from a tuft of hair dipped into the fluid. 
Kre'a-tin. (310.) A constant constituent 

of the juices of muscles. 

La'bi-um.jj/. La'bi-i. [L.] The lips. 

Lab'y-rinth. (435.) [Gr.] The internal 
ear : — so named from its many windings. 

Lach'ry-mal. (446.) [L. lachryrna, a tear.] 
Pertaining to or secreting tears. 

Lac'te-al. (277.) [L. lac, milk.] A small 
vessel or tube of animal bodies for con- 
veying chyle from the intestines to the 
thoracic duct. 

Lac'tin. (215.) [L. lac, milk.] Lactose, 
or milk-sugar. 

Lac'to-Pro'te-in. (229.) An albuminoid 
substance found in milk. 

La-cu'na, pi. La-cu'nae. (505.) [L. lacus, 
a ditch or hole.] Small pits in the mu- 
cous membrane ; also in the bones. 

La'cus. [L.] A small space in the inner 
angle of the eye between the lids. 

Lam'i-na, pi. Lam'i-nae. [L.] A plate or 
thin coat lying over another. 

Lar-yn-gri'tis. Inflammation of the larynx. 

La-ryn' go-scope. [Gr. lanuix, larjnx, and 
skopeo, to look at.] An instrument by 
which the larynx can be viewed in the 
living subject. 

Lar'ynx. (487.) [Gr. lanmx.] The upper 
part of the windpipe. The organ of the 
voice. 



GLOSSARY. 



357 



La'tent. [L. lateo, to lie hid.] Concealed ; 
waiting for a favorable opportunity. 

Lat'e-ral. [L. latu^, the side.] Belonging 
to the side. 

La-tis'si-mus, pL La-tis' si-mi. [L., su- 
perlative of latus, broad.] A term ap- 
plied to some muscles. 

La-trine'. A water-closet. 

Le-gu'min. (217.) Cheese or vegetable 
casein found in peas, beans, etc. 

Le'sion. [L. liedo, Isesum, to hurt.] A 
wound, hurt, or vitiated condition of a 
part. 

Leu'cin. (310.) One of the principal prod- 
ucts of the decomposition of nitroge- 
nous matter. It forms thin, white, flat 
crystals. 

Le-va'tor. [L. levo, to raise.] A name 
applied to a muscle that raises the part 
to which it is attached. 

Lig'a-ment. (509.) [L. Ugo, to bind.] A 
strong, compact substance serving to 
bind one bone to another. 

Ligr'a-ture. (105.) A thread of silk, flax, 
silver, etc., suitable for tying arteries 
and veins. 

Lig'nin. (230.) The woody fibre of vege- 
table substances. 

Lin'e-a, pi Lin'e-se. [L.] A line. 

Lin'gvLSi, pi. Lin' gxiae. [L.] A tongue. 

Lobe. A round or projecting part of an 
organ. 

Lob'u-lar, Lob'u-lat-ed. (163.) [L. hbu- 
Im.] Shaped like a lobe or lobules. 

Lo-cal-i-za'tion. The act or power of 
locating a sensation. 

Lon'gus, Lon'gi-or. [L., long, longer.] A 
term applied to several muscles. 

Lo'tion. [L. lotio, a wash'.] A medicated 
fluid used as an external apjilication. 

Lu'bri-cant. [L. Inbricans.] That which 
makes smooth or slippei'y. 

Lum'bar. [L. Imnbm, the loins.] Pertain- 
ing to the loins. 

Lu'men. [L., light, pupil.] The calibre 
of an anatomical tube or vessel. 

Lu'na-cy. [Tj. ?»}(«, the moon.] Insanity 
in which there are lucid or normal in- 
tervals. 

Lymph. {2\V).) [L. li/mpha, water.] A 
colorless fluid in animal bodies, con- 
tained in vessels called lymphatics. 



Lym-phat'ic. A vessel of animal bodies 
that contains or conveys lymph. 

Mag'nus, -na, -num. [L., great.] A term 

applied to certain muscles. 
Maize. Indian corn {Zea mays). 
Ma'jor. [L., greater.] Greater in extent 

or quantity. 
Mal-aise'. [Fr. mul, ill, and aise, ease.] 

Discomfort; uneasiness. 
Ma-la'ri-a. [Ital. mala, bad, and aria, 

air.] A term for the disease-inducing 

agents arising from decaying organic 

materials. 
Mal-for-ma'tion. A deviation from the 

normal form of a part. 
Mal'le-us. (433.) [L., a hammer.] A bone 

of the middle ear. 
Mam'mal. [L. mamma, a breast.] An 

animal that suckles its j'oung. 
Ma'ni-a. (400.) [Gr. mainomai, to rage.] 

Madness; delirium not occasioned by 

fever-action. 
Man'like Apes. The chimpanzee, gorilla, 

ourang, and gibbon. 
Mar-gar'ic. (219.) An acid intermediate 

between palmitic and stearic acid of 

fats. 
Mar' row. [Sax.] A soft, oleaginous sub- 
stance contained in the cavities of bones. 
Mas-se'ter. [Gr. irtassaomoi, to chew.] The 

name of a muscle of the face. 
Mas-ti-ca'tion. (258.) [L. mnstko, to 

chew.] The act of chewing. 
Mas'toid. [Gr. mastos, the breast, and eidos, 

form.] The name of a process of the 

temporal bone behind the eai*. 
Mas-toid'e-us. A name applied to mus- 
cles that are attached to the mastoid 

process. 
Ma'trix. (34.) [Gr. vinler, a mother.] The 

place or substance in which anything is 

formed. 
Max-il'la. [L.] The jaw-bone. 
Max'i-mus, -um. [L., superlative of ttiaij- 

VHS, great.] A term applied to several 

muscles. 
Me-a'tus. [Ij. >ii<-i\ to go.] A passage or 

channel. 
Mech'an-ism. An assemblage of cells or 

parts to perform a special fiuictiou or 

action. 



358 



GLOSSAEY 



Me-di-as-ti'num. A membrane that sepa- 
rates the chest into two parts. 

Me'di-um, pi Me'di-a. (457.) [L.] A 
transparent or translucent solid, fluid, 
or gas. 

Me-dul'la Ob-lon-ga'ta. (365.) The com- 
mencement of the spinal cord. 

Me-dul'la Spi-na'lis. The spinal cord. 

Med'ul-la-ry. il6.j [L. medulla, marrow.] 
Pertaining to marrow. 

Med'ul-la-ry Sub' stance. (39.) A line of 
colored, irregularlv-shaped cells, which 
run through the centre of a hair. 

Mem-bra'na. ("26. » A membrane ; a thin, 
white, flexible, skin -like expansion, 
formed by fibres interwoven like net- 
work. 

Mes-en-ter'ic. Pertaining or belonging 
to the mesentery. 

Mes'en-ter-y. (264.) [Gr. mesos, the mid- 
dle, and enteroii, the intestine.] The 
membrane in the middle of the intes- 
tines by which they are attached to the 
spine. 

Met-a-car'pus. [Or. meta, after, and larpos, 
the wrist.] The part of the hand be- 
tween the wrist and the fingers. 

Met-a-tar'sus. [Gr. meta, after, and tarsos, 
the tarsus.] The instep : — a term applied 
to seven bones of the foot. 

Mg, The chemical symbol of magnesium, 
the base of magnesia. 

Mi-cro-ce-phal'ic [Gr. mikros, small, and 
l:ephaU. the head.] Eelating to persons 
having abnormally small heads. 

Mi'cro-scope. [Gr. mikros, small, and 
shopeo, to look at.] An optical instru- 
ment employed in the study of minute 
objects. 

Mid'dle-men. Agents between two parties; 
arrangers of impulses. 

Mid'rlff. [Sax. mid, and Jirife, the belly.] 
See Diaphragm. 

Min'i-mus. [L.] The smallest: — a term 
applied to several muscles. 

Mi'nor. [L.] Less, smaller: — a term ap- 
plied to several muscles. 

Mi'tral. (93.) [L. mitra, a mitre.] The 
name of valves in the left side of the 
heart. 

Mixed Nerve. A compound of motor and 
sensoi-y fibres. 



Mo-di'cus. [L. modus, a measure.] A cone 
in the cochlea around which the mem- 
branes wind. 

Mo'lar. 1254.) [L. mola, a mill.] The 
name of some of the large teeth. 

Mo-lec'u-lar. Pertaining to molecules, a 
collection of elementary atoms joined 
together. 

Mol'lis. [L.] Soft. 

Mor'pM-a. [From :Morpheus, the god of 
sleep.] The most important narcotic 
principle of opium. 

Mo'tor, J)?. Mo-to'res. [L.] A mover:— a 
term applied to certain nerves. 

Mu'cous. Pertaining to mucus. 

Mu'cus. A viscid fluid secreted by the 
mucous membrane, which it serves to 
moisten and defend : animal mucilage. 

Mus'cae Vol-i-tan'tes. (461.) [L., hov- 
ering flies.] Mote-like objects hovering 
in the field of sight. 

Mus'eu-lar Sense. See *" 472. It is some- 
times called the sixth sense. 

My-o-lem'ma. [Gr. mus, a muscle, and 
lemma, a sheath.] The investing mem- 
brane of muscular fibre. 

My-ol'o-gy. [Gr. mns, a muscle, and logos, a 
discourse.] A description of the muscles. 

My-op'ic. (460.) [Gr. mtio, to contract, 
and ops, the eye.] (Xear-sighted persons 
partially close the eyes when looking at 
distant objects.) Eelating to near-sight. 

N. The chemical symbol of nitrogen. 

Na. [L. uatrium.] The chemical symbol 
of sodium, the base of soda. 

Nar-cot'ic. (188.) [Gr. narle, stupor.] A 
medicine which induces stupor or sleep. 

Na'sal. Eelating to the nose. 

Nau'se-a. [Gr. nans, a ship.] Any sick- 
ness at the stomach, similar to com- 
mencing sea-sickness. 

Nerve. (^S0^ The fibres of the animal 
body which transmit impulses. 

Nerve'-Cen-tre. (84.) A group of nerve- 
cells. It can originate, receive, and 
modify impulses. 

Ner'vous-ness. Unusual impressibility of 
the brain-centres: "brain-fag.'" 

Neu-ral'gi-a. (^379.) [Gr. neuron, a nerve, 
and algos, pain.] Pain in the course of 
a nerve. 



GLOSSARY. 



359 



Neu-ri-lem'ma. [Gr. neuron, a nerve, and 
lemma, a sheath.] The sheath or cover- 
ing of a nerve. 

Neu-rol'o-gy. [Gr. neuron, a nerve, and 
logos, a discourse.] A description of the 
nerves of the body. 

Nic'o-tin. (412.) The colorless, poisonous, 
and stupefying odorous oil extracted 
from tobacco. 

Nor'mal. [L. norma, a rule.] Of the reg- 
ular type or form. 

Nu'cle-a-ted. Having a nucleus or cen- 
tral particle. 

Nu-cle'o-lus. (8.) The small body seen 
within the nucleus. 

Nu'cle-us. (8.) [L., a kernel.] The small 
mass seen within the cell-body. 

Nu-tri'tion. (308.) [L. nutrio, nutritum, to 
nourish.] Assimilation ; the act of nour- 
ishing. 

0. The chemical symbol of the element 

oxygen. 
Ob-jec'tive. The combination of small 

lenses at the lower end of the tube of 

the microscope. 
Oc-cip'i-tal. Pertaining to the occiput. 
Oc'ci-put. [L. ob, and caput, the head.] 

The back part of the head, formed by 

the occipital bone. 
Oc'u-lar. (443.) Belonging to the eye. 
Oc'u-lo-Mo'tor. The nerve or muscle 

concerned in moving the eyeball. 
Oc'u-lus, p?. Oc'u-li- [L.] The eye. 
CE-soph'a-g:us. (260.) [Gr. oio, to carry, 

and phnijo, to eat.] The name of the 

passage through which the food passes 

from the mouth to the stomach. 
0-lec'ra-non. [Gr. oloie, the ulna, and 

Jn-uvoii, the head.] The elbow ; the head 

of the ulna. 
O'le-ic A^'id. (211).) One of the acids 

of fat. It is a fluid. 
01-fac'to-ry. [L. oleo, to smell, and facio, 

to make.] Pertaining to smelling. 
Ol'i-va-ry. Like an olive : — a term applied 

to the oniini^nce.s of the niodtilla. 
0-men'tum. [L.] The caul. 
O'mo. [(Jr. ())((((N, the shoulder.] The Uiuue 

of nuisi'h^s attached to the slumldcr. 
Oph-thal'mic. [(!r. ophthahtiox, the eye.] 

Belonging to the eye. 



Oph-thal'mo-scope. [Gr. opJithalmos, the 
eye, and slcopeo, to look at.] An instni- 
ment used in examining the interior of 
the globe of the eye. 

O'pi-um. (411.) [Gr. opos, juice.] The 
concrete juice of the Papaver somnifenim. 
It is a stimulant narcotic. 

Op'tic Thal'a-mi. See % 353. 

Or-bic'u-lar. [L. orbis, a circle.] A cir- 
cular or sphincter muscle. 

Or' bit. (340.) The bony cavity in which 
the eye is placed. 

Or-gan'ic. Having an organized struc- 
ture ; relating to organs. 

Or'gan-ized. (122.) Having a defined 
structure. 

Or'i-gin. (513.) The source of a muscle's 
attachment. 

Os. [L.] A bone ; the mouth of anything. 

Os'mose, Os-mo'sis. (275.) [Gr. osmos, 
impulse.] The mixing of fluids through 
a moist membrane or porous substance. 

Os'se-ous. Pertaining to bones. 

Os-si-fi-ca'tion. (504.) The process of 
bone -formation. 

Os'si-fy. [L. OS, a bone, and facio, to 
make.] To convert into bone. 

Os-te-ol'o-gy. [Gr. osteon, a bone, and logos, 
a discourse.] The part of anatomy which 
treats of bones. 

O'vum. [L., an egg.] The germ before 
impregnation. It is the product of the 
ovary. 

Ox-i-da'tion. (313.) The chemical union of 
oxygen with other substances ; burning. 

Ox'y -Hae-mo-glo'bin. (181.) Oxygen 
loosely combined with haemoglobin in 
the blood. 

P. The chemical symbol of the element 
lihosjihorus. 

Pab'u-Ium. [L-, from ptisco, to feed.] 
Food ; aliment ; sustenance. 

Pa-la' turn. [L.] The palate ; the roof of 
the mouth. 

Pal'lor. [From /.<,//,<>. to be pale.] Pale- 
ness ; loss of color. 

Palm. The hollow or inside of the hand. 

Pal'mar. | L. ^xi/di.;, tlu- palm.] Pelong- 
ing to the hand. 

Pal-ma'ris. A term applied to some mus- 
cles attached to the palm of the hand. 



360 



GLOSSARY. 



Pal-mit'ic. (219.) A colorless, solid, taste- 
less body found in certain oils. It is an 
acid in action. 

Pal'pe-bral. (444.) Belonging to the eye- 
lids. 

Pal-pe-bra'rum. [L. paJpehra, the eyelid.j 
Of the eyelids. 

Pan'cre-as. [Gr. pan, all, and Ireas, flesh.] 
The name of one of the digestive organs. 

Pan'cre-a-tin. The albuminous ingredient 
of the pancreatic juice. 

Pa-pil'la, jjZ. Pa-pil'lse. (30.) [L.] Small 
conical prominences. 

Pap'il-la-ry. (97.) Pertaining to the 
papillae. 

Pa-ral'y-sis. Abolition of function, 
whether of Intellect, sensation, or mo- 
tion. 

Par-a-ple'gi-a. [Gr. benumbing of parts.] 
Palsy affecting one-half the body, usually 
the lower portion. 

Pa-ren'chy-ma. [Gr. paregchuo, to pour 
through.] The substance contained be- 
tween the blood-vessels of an organ. 

Pa-ri'e-tal. [L. paries, a wall.] A bone 
of the skull. 

Pa-rot'id. (257.) [Gr. para, near, and otos, 
genitive of ous, the ear.] The name of 
the largest salivary gland. 

Pas'sive. Acted upon ; not acting of itself. 

Pa-tel'la, pi. Pa-tel'lae. [L.] The knee- 
pan. 

Pa-thet'i-cus, /jL Pa-thet'i-ci. (382.) [Gr. 
pathos, passion.] The name of the fourth 
pair of nerves. 

Path-o-log'i-cal. [Gr. pathos, disease, and 
logos, a discourse.] Belonging to dis- 
ease, or to disease-action. 

Pec'to-ral. [L.] Pertaining to the chest. 

Pe'dis. [L., genitive of pes, the foot.] Of 
the foot. 

Pe-dun'cles. (352.) [L. pes, pedunculus, 
diminutive of a foot.] The foot-stalks 
of the bi-ain. 

Pel'vis. (247.) [L.] The basin formed 
by the larger bones at the lower part 
of the abdomen. 

Pep'sin. (262.) [Gr. pejHo, to cook.] An 
ingredient of the gastric juice which acts 
as a ferment in the digestion of the food. 

Pep'tone. (274.) A proteid soluble in 
water and not coagulable by heat. 



Per-cep'tion. The act of receiving knowl- 
edge of external objects by impres- 
sions on the senses ; intellectual dis- 
cernment. 
Per-i-car'di-um. (95.) [Gr. peri, around, 
and kardia, the heart.] A membrane 
that invests the heart. 
Per'i-lymph. (440.) [Gr. peri, around, 
and hjmpha, watery fluid.] The fluid of 
the internal ear. 
Per-i-mys'i-um. [Gr. peri, around, and 
mus, a muscle.] The investing mem- 
brane of a muscle. 
Per-i-os'te-um. (16.) [Gr. peri, around, 
and osteon, a bone.] The white mem- 
brane investing the bone. 
Per-i-stal'tic. (265.) [Gr. pen, around, 
and stello, I contract.] A movement like 
the crawling of a worm. 
Per-i-to-ne'um. (246.) [Gr. peri, around, 
and teinein, to stretch.] A thin, serous 
membrane investing the internal sur- 
face of the abdomen. 
Per-me-a'tion. [L. per, through, and meo, 
to pass.] The passing of a substance 
through the pores of a body. 
Per-o-ne'al. [Gr. perone, the fibula.] Per- 
taining to the external bone of the 
leg. 
Per'so-nal E-qua'tion. See ^ 361. 
Per-spi-ra'tion. (46.) [L. per, through, 
and spire, to breathe.] Excretion by the 
skin. 
Per-ver'sion. A departure or change from 

the normal action. 
Pha-lan'ge-al. Belonging to the fingers 

or toes. 

Pha'lanx, jol Pha-lan'ges. [Gr. phalanx, 

an army.] Three rows of small bones 

forming the fingers or toes. 

Pha-ryn'ge-al. Relating to the pharynx. 

Phar'ynx. (158.) [Gr. j^lMnrnx.] The 

upper part of the o'sopliagus. 
Phos'pho-rus. [Gr. phos, the light, and 
phero, to bear.] A combustible sub- 
stance, of a yellowish color, semi-trans- 
parent, resembling Avax. 
Phren'ic. [Gr. phren, the diaphragm, or 
parts adjacent to the heart.] Belong- 
ing to the diaphragm. 
Phthi'sis (pronounced thi'sis.) [Gr. phthio, 
to consume.] Pulmonary consumption. 



GLOSSARY. 



361 



Phys-i-ol'o-g-y. (1.) [Gr. pftwsis, nature, 
and logos, a discourse.] The science of 

. the functions of the organs of animals 
and plants. 

Pi-a Ma'ter. (3G7.) [L., tender mother.] 
The most internal of the three brain- 
membranes. 

Pig-men' turn Ni'grum. [L.] Black paint. 
See T[ 451. 

Pin'na. (^8'2.) [L., a wing.] A jjart of 
the external ear. 

Plas'ma. (122.) [Gr. jj^asso, to form.] The 
fluid in which the blood-corpuscles float ; 
the serum. 

Pla-tys'ma. (88.) [Gr. plains, broad.] A 
muscle of the neck. 

Pled'get. A piece of cotton or lint rolled 
in an oval form. 

Pleth'o-ra. (334.) [Gr. ^jfe^/io, to be full.] 
Excessive fulness of the vessels or of 
the body. 

Pleu'ra, jjZ. Pleu'rae. (155.) [Gr. pleura, 
the side.] A thin membrane that covers \ 
the inside of the thorax and also forms 
the exterior coat of the lungs. 

Plex'us. [L plecio, to weave together.] j 
Any union of nerves, vessels, or fibres, 
in the form of net-work. 

Pneu-mo-gas'tric. (383.) [Gv.imemnon,i\\G 
lungs, and (juster, the stomach.] Belong- 
ing t(' both the stomach and the lungs. 

Pneu-mo-ni'tis. [Gr. pnemnon, the lungs.] 
Pneumonia; inflammation of the lungs. 

Pol'li-cis. [L.] A term applied to muscles 
attached to the fingers and toes. 

Pons. (366.) [L.] A bridge. Pons Varolii, 
a part of the brain formed by the union 
of the crura cerebri and cerebelli. 

Pop-lit'e-al. [L. poplrs, the ham.] Per- 
taining to the ham or knee-joint. 

Por'tal. (103.) [L. porta, a gate.] Ec- 
lating to the vessels entering the fissure 
of the liver. 

Por'ti-o Du'ra. [L., hard iiortion.J Tlu> 
facial nerve; seventh pair. 

Por'ti-o Mol'lis. [L., soft portion. | The 
auditory nerve ; eighth pair. 

Pre-hen'sion. |Ij. prcliciitlo, iinhruaiuii, to 
lay liold on. I The act of grasping. 

Pre-mo'lar. C2'>\.) \h. /))vr, before, and 
)ii()liuis, intilar. 1 Tlie Cirst two pairs of 
molar teeth ; the bicuspids. 

Q ol 



Pres-by-op'ic. [Gr. presbus, an old man, 
and ops, the eye.] Relating to the de- 
fective vision (long sight) of old per- 
sons. 

Press'ure Sen-sa'tions. (469.) Tactile 
sensations. 

Pro-bos' cis. [Gr j^ro, before, and bosko, to 
feed.] The snout or trunk of an ele- 
phant or other animal. 

Prog'ess. A prominence or projec- 
tion. 

Pro-fun' da. [L., deep.] Aijplied to vessels 
and nerves from their relatively deeper 
position. 

Pro'te-ids. (215.) [From Pro<eHS, who could 
assume difl'erent shapes.] A name given 
to a class of chemical com^jounds made 
exclusively by plants, and composed of 
C, H, 0, N, S, with Ca and P. 

Pro'to-plasm. (9.) [Gr. j)rotos, first, and 
plasma, formed.] Bioplasm. 

Pseu-do-po'di-a. (6.) [Gr. pseiules, false, 
and podos, a foot.] Blunt, finger-like 
processes. 

Pso'as. [Gr. psoai, the loins.] The name 
of two muscles of the thigh. 

Psy'chi-cal, [Gr. psuche, soul or mind.] 
Belonging to the mind or intellect. 

Pty'a-lin. The active principle of sMiva. 

Pu'bic. Pertaining to the pubis. 

Pul-mon'ic, "j 

Pul'mo-na-ry, > [L. puhiio, the lungs.] 

Pul-mo-na'lis. ) 
Belonging or relating to the lungs. 

Pul'que (pronounced pool'kay). An alco- 
holic intoxicant made from the Agare 
Mexicana in Mexico. 

Pulse. (144.) [L. pello, pulsinu, to beat, 
to strike.] The beating of the arteries 
following the contraction of the heart- 
muscle. 

Punc'ta. (447.) [L.] A point. 

Pu'pil. A little aperture in the centre 
of file iris, through which the rays of 
light pass to the retina. 

Py-lor'ic. (262.) Pertaining to tl>e i>\ lorus. 

Py-lo'rus. [Gr. puloros, a gate-keeper.] 
The lower orifice of the stomach. 

auad-ra'tus. [!'• <ii<a<lr.,, a s.nuuv.] Of 
a sijuare flgure; quadrate; i|nadrangu- 
lar:— applied to certain muscles. 



362 



GLOSSARY. 



Ra'bi-es. [L. rabio, to be mad.] A dis- 
ease caused by the absorption through a 
scratch or wound of the saliva of a mad 
animal, inducing hydrophobia, or dread 
of water. 

Ra'di-ate. Having lines or fibres that 
diverge from a point. 

Ra-di-a'tion. (319.) The direct passing 
away of heat into the air from a warm 
body. 

Ra'di-us. [L., a ray, a spoke of a wheel.] 
The name of one of the bones of the 
forearm. 

Ra'mus. [L.] A branch. 

Re-ac'tion. (62.) The vigorous acting 
again of the vital powers after they 
have been depressed. 

Re-ac'tion Pe'ri-od. See ^^f 360, 361. 

Re'cent. (70.) New; fresh. 

Ree'tum. (268.) The third and last por- 
tion of the intestines. 

Rec'tus, 25?- Rec'ti. [L.] Straight; erect: 
— a term applied to several muscles. 

Re-cu-per-a'tion. Recovery; restoration. 

Re-duc'ing A'gents. (180.) A term ap- 
plied to chemical bodies whose action is 
the reverse of that of oxygen, like nas- 
cent hydrogen. 

Re'flex Ac'tion. (82.) A term applied to 
certain movements executed indepen- 
dent of the will. 

Re-frac'tion. [L. re, again, and frango, 
fraction, to break.] See f 457. 

Reg'i-men. [L. rego, to govern.] The 
systematic regulation of the food and 
drink. 

Re'Iays. (375.) Local nerve-mechanisms 
w^hich, under the spur of slight impulses, 
carry into effect complicated activities. 

Re-mak's' Nerve-Fibres. (79.) Named 
after a German physiologist. 

Re'nal. (300.) [L. ren, the kidney.] Be- 
longing to the kidney. 

Re-pro-duc'tion. [L. re, again, and pro- 
diico, jyroductum, to bring forth.] The 
production by organized bodies of others 
similar to themselves. 

Re-sid'u-um. [L.] Waste matter. 

Res-pi-ra'tion. (177.) [L. re, again, and 
spiro, to breathe.] The act of breathing. 

Re-spi'ra-to-ry Cen'tre. (185.) A nervous 
mechanism of the medulla. 



Retch'ingr. Continued efforts to vomit 
independent of the will. 

Re'te Mu-co'sum. (29.) [L., mucous net- 
work.] The substance in the skin con- 
taining the pigment. 

Re-tic'u-lar. [L. rete, a net.] Resembling 
a net. 

Ret'i-na. (451.) [L. rete, a net.] The 
essential organ of sight. One of the 
coats of the eye, formed by the expan- 
sion of the optic nerve. 

Ret'i-nal Ex-haus'tion. See ^ 465. 

Rhyth'mic. (133.) [Gr. rhuthmos, meas- 
ured movement.] Succeeding one an- 
other at regular intervals. 

Rick'ets. (335.) A disease of children 
characterized by a large head, crooked 
spine and limbs, tumid abdomen, and 
general debility. 

Ri-so'ri-us. [L. rideo, risiim, to laugh.] 
The laughing muscle of Santorini, — a 
thin muscle acting at the angle of the 
mouth. 

Ro-tun'dum, [L.] Round; circular. 

Ru'ga, jj?. Ru'gse. A wrinkle ; a fold. 

S. The chemical symbol of the element 
suljAur. 

Sac'cu-lus. [L., diminutive of saccus, a 
bag.] A little sac. 

Sa'cral. Pertaining to the sacrum. 

Sa'crum. (247.) [L., sacred.] The bone 
which forms the posterior part of the 
pelvis. 

Sa'ke. A light wine made from rice by 
the Japanese. 

Sa-li'va. (257.) [L.] The fluid secreted 
by the salivary glands, Avhich moistens 
the food and the mouth. 

Sam-shoo'. An intoxicant used by the 
Chinese. It is made from rice by dis- 
tillation. 

San-guin'e-ous. [L. sanguis, the blood.] 
Bloody; abounding with blood; ple- 
thoric. 

Sar-co-lem'ma. (71.) [Gr. sarx, flesh, and 
lemma, a covering.] The thin sheath 
enclosing muscular fibrils. 

Sar'cous. (71.) [Gr. saiw, flesh.] Pertain- 
ing to flesh or to muscular fibre. 

Sar-to'ri-us. [L. sartor, a tailor.] A term 
applied to a muscle of the thigh. 



GLOSSARY. 



363 



Sca'la, pi. Sca'lse. (435.) [L., a ladder.] 

Cavities of the cochlea. 
Sca-le'nus. [Gr. skalenos, unequal.] A 
term applied to some muscles of the neck. 
Scalp. The integument of the skull. 
Scal'pel. [L. sculjjo, to carve or scrape.] 
A small knife with a straight blade fixed 
in a flat handle. 
Sca'phoid. [Gr. slcaphe, a little boat.] The 
name applied to one of the wrist-bones. 

Scap'u-la. [L.] The shoulder-blade. 

Soap'u-lar. Eelating to the scai)ula. 

Sci-at'ic. [Gr. hchiwi, the haunch.] Per- 
taining to the loins: — applied to the 
large nerve of the loins and legs. 

Scle-rot'i-ca. (451.) [Gr. sUei-os, hard.] 
One of the tunics of the eyeball. 

Scur'vy. (225.) Scorbutus; — a disease of 
the general system, having prominent 
skin-symptoms. 

Se-ba'ceous. (41.) [L. se/*«//*, tallow.] Per- 
taining to fat. 

Se-cre'tion. The act of producing from 
the blood substances different from the 
blood itself; the matter secreted, as mu- 
cus, bile, saliva, etc. 

Se-cun'dus. [L.] Second :— a term applied 
to certain muscles. 

Sed'en-ta-ry. [L. sedere, to sit.] Accus- 
tomed to sit much and long. 

Selt'zer. Water impregnated with car- 
bonic acid gas; also, water containing 
carbonates of the alkalies and alkaline 
earths ; soda-water. 

Sem-i-cir'gu-lar. (435.) Having the form 
of a half-circle :— applied to a part of the 
ear. 

Sem-i-lu'nar Valves. (92.) [L. semi, half, 
and /((//((, the moon.] The name of the 
three festooned valves of the heart at 
the entrance of the great arteries. 

Sem-i-ten-di-no'sus. [L. wwj, half, and 
toido, a tendon.] The name of a niusclo. 

Sen-sa'tion. The consciousness of the 
reception of an impulse. 

Sep'tum, ]>I. Sep'ta. [L.] A membrane 
that divides two cavities from each other. 

Se'rous. (156.) Thin; watery; pertain 
ing to serum. 

Ser-ra'tus. (172.) [L. s,>n;>, to saw.] A 
term applied to some nnistlos of tlie 
trunk. 



Se'rum. (115.) [L.] The thin, transpa- 
rent part of the blood. 
Sew'er-Gas. (199.) The complex gases 
developed by decomposition of organic 
materials in sewers and cesspools. 
Si. The chemical symbol of the element 
silicon, the chief ingredient of silex and 
sand. 
Sig'moid. [Gr.] Resembling the Greek 

letter s (sigma). 
Si'nus. [L., a bay.] A cavity the interior 
of which is more exjjanded than the en- 
trance. 
Skel'e-tal Mus'cles. Muscles attached 
directly or indirectly to the bony frame- 
work. 
Skel'e-ton. (17.) [Gr. skello, to dry.] The 
aggregate of the hard parts of the body ; 
the bones. 
Smell' ing Salts. Carbonate of ammonia. 
Snel'len's Types. (463.) Types used to 

test the range of vision. 

Soaps. (274.) Compounds made by the 

action of soda or potassa with fatty acids. 

SoftWa'ter. (479.) A water which readily 

yields a lather with soap ; a water free 

from lime-salts. 

So'lar. [L. sol, the sun.] Pertaining to, 

or derived from, the sun. 
So-lu'tion. [L. solro, fiohitmn, to dissolve, 
to loosen.] Any substance dissolved in a 
liquid. 
So-pra'no. The treble ; the highest female 

voice. 
Spasm. A sudden contraction of muscu- 
lar fibres independent of the will. 
Spe'cies. An assemblage or series of simi- 
lar organic beings. 
Sphe'noid. [Ga. .^phou a wedge, and eidos, 
likeness.] A bone at the base of the 
skull. 
Spher'i-cal A-ber-ra'tion. (461.) Defects 
in the rt>fiacting i^ower of the lens trom 
the centre to the circumference. 
Sphinc'ter. [Gr. s:phi)i,io, to restrict.] A 
muscle that contracts or shuts an ori- 
fice. 
Spi'nal Ac'ces-so-ry- The eleventh cm- 
nial ])air. It is accessory to the vagus 
luMve. 
Spi'nal Cord. A prolongation of the 
brain. 



364 



GLOSSAEY. 



Spine. A thorn. The vertebral column ; 
the backbone. 

Spi'nous. Pertaiuing to the vertebral 
column. 

Spir'its. A name given to liquid products 
of distillation. The term is confined to 
the stronger beverages, like rum, gin, 
whiskey, brandy, etc. 

Splanch'nic. [Gr. splanchnon, a viscus.J 
Pertaining to the viscera. 

Splanch-nol'o-gy. [Gr. splanchnon, the 
bowels, and logos, a discourse.] A descrip- 
tion of the internal parts of the body. 

Splen'ic. Pertaining to the spleen or milt. 

Sple'ni-us. The name of a muscle of the 
neck. 

Split' ting-up. (213.) The breaking up of 
a complex organic molecule, under the 
influence of warmth and moisture, into 
compounds of a simpler chemical nature, 
like water, carbonic acid, etc. 

Spon-ta'ne-ous. [L. sponte, of one's own 
free will.] Taking place without exter- 
nal stimuli. 

Spu-tum, pi. Spu-ta. [L. spuo, sputum, to 
spit.] The matter which is coughed up 
from the air-passages. 

Sta'pes. (433.) [L., a stirrup.] One of 
the bones of the internal ear. 

Starch. (220.) [L. anujhun and fee ula.] One 
of the main proximate principles of seeds. 

Ste'a-rin. [Gr. stem; suet.] One of the 
proximate principles of animal fat. It 
is solid at ordinary temperature. 

Ster'num. The breast-bone. 

Stim'u-lant. (237.) A drug or agent 
which excites the organic action of the 
animal system. 

Stim'u-lus. Something which excites the 
tissues or parts to action. 

Stra'tum. [L. sterno, to spread.] A bed ; 
a layer of anything. 

Stri'se. (71.) [L., a groove, a crease.] 
Marks seen on certain fibres. 

Sty'loid. [L. stijlus, a pen.] Pen-like:— 
an epithet applied to processes that re- 
semble a style, or pen. 

Sub. [L.] Under; beneath. 

Sub-ar-ach-noi'de-an. (368.) [L. sub, 
under, Gr. arachne, a spider's web, and 
eidos, form.] Situated under the arach- 
noid membranes. 



] Sub-cla'vi-an. [L. sub, under, and clavU, 

a key.] Situated under the clavicle. 
[ Sub-cu-ta'ne-ous. [L. s?t6, under, and cttiis, 
j the skin.] Situated under the skin. 

Sub-ja'cent. (156.) | [L. sub, under, and 

jacere, to lie.] Lying under or beneath. 

I Sub-lin'gual. (257.) [L. sub, under, and 

j lingua, the tongue.] Situated under the 

I tongue. 

j Sub-max'il-la-ry. (257.) [L. sub, under, 
and maxilla, the jawbone.] Located under 
the jaw. 

Sub-mu'cous. [L. sub, and luucus.] Placed 
under the mucous membrane. 

Sub-or'di-nate. [L. sub, under, and ordi- 
nare, to set in order.] Placed in a lower 
order or position. 

Sub' soil. (202.) The soil lying under the 
black or cultivated earth. 

Su-i-ci'dal. [L. siii, of himself, and cidium, 
slaying.] Partaking of self-murder. 

Sul'cus, pi. Sul'ci. A groove or trench, as 
of the surface of the brain. 

Su-pi-na'tor. [L.] A muscle that turns 
the palm of the hand iipward. 

Sup-pos'i-to-ry. (292.) A medicated, but- 
ter-like mass placed in the rectum to be 
dissolved. 

Su'ture. [L. suo, to sew.] The seam or 
joint that imites the bones of the skull. 

Sym-met'ri-cal. The resemblance exist- 
ing in many organs or parts situated on 
each side of the median line." 

Sym-pa-thet'ic Sys'tem. (386.) The sys- 
tem of organic life ; the ganglionic sys- 
tem. 

Syn-ar-thro'sis. [Gr. sun, with, and ar- 
tlirov, a joint.] An immovable articula- 
tion. 

Sy-no'vi-a. (.508.) [Gr. sun, with, and 
oova, an egg.] The fluid secreted into 
the cavities of joints for the purpose of 
lubricating them. 

Sys'tem. An assemblage of organs com- 
posed of similar tissues and intended for 
the same functions. 

Sys-tem'ic. Belonging to the general 
system. 

Sys'to-le. (125.) [Gr. s?(s^e?/o, to contract.] 
The contraction of the heart and arteries 
for expelling the blood and carrying on 
the circulation. 



GLOSSARY. 



365 



Tac'tile. (467.) [L. taclns, toucli.] Per- 
taining to the sense of touch. 

Tal'lah. An alcoholic intoxicant made 
from millet by the Abyssinians. 

Tar'sus. [L.] The posterior part of the foot. 

Tem'per-a-ture. (470.) A definite or cer- 
tain degree of sensible heat, as measured 
by a thermometer. 

Tem'po-ral. [L. temims, time.] Pertain- 
ing to the 1 emple region. 

Ten' don. [Gr. teino, to stretch.] A hard, 
insensible cord, or bundle of fibres, by 
which a muscle is attached to a base. 

Ten' or. The higher of the two kinds of 
voices usually belonging to adult males. 

Ten'sion. The state of being stretched ; 
the state of being bent or strained into 
action. 

Ten'sor. A muscle that extends a part. 

Ten-to'ri-um. [L. tendo, to stretch.] A 
process of the dura mater which lies be- 
tween the cerebrum and the cerebel- 
lum. 

Te'res. [L.] Round :— a term applied to 
many organs, the fibres of which are col- 
lected in small bundles. 

Test. In chemistry, anything by which 
the nature ofa substance is distinguished. 

Tet'a-nus. (75.) [Gr. teino, to stretch.] 
Spasms with rigidity, continuing for 
some time. The muscles of the jaw 
being involved, lock-jaw occurs. 

The'in, (238.) [L. thea, the tea-plant.] 
The active principle of tea. 

Tho-ra'cic Duct. (277). The principal 
tube of the lymphatic system. 

Tho'rax. (89.) [Gr.] That part of the 
skeleton that composes the bones of the 
chest; the cavity of the chest. 

Thy'roid. (488.) [Gr. t.hnreoK, a shield.] 
Resembling a shield :— applied to a cur- 
tilage of the larynx. 

Tib'i-a. [L., a flute.] The large boii(> of 
the leg. 

Tis'sue. The toxtinv or organi/.ation of 
parts. 

Ton'ic Ac'tion. The state of a part when 
under moderate, continued, muscular- 
action pressure. 

Ton'ics. Medicines whicli i»nidnce a grad- 
ual but permanent excitement of the 
vital functions. 



Ton'sil. (251.) [L.] A glandular body 
in the throat or fauces. 

Tra'che-a. [Gr. trachua, rongh.] The wind- 
pipe. 

Tract. The space, region, or course of 
fibres, as of the optic tract. 

Train'ing:. (534.) The preparing of an 
animal for sustained athletic exercises. 

Tran'sit. The passage of a celesfrfal body 
across the meridian wire of the tele- 
scope. 

Trans-mis' sion. (399.) The passing of 
mental, moral, and physical peculiarities 
from father to son, son to grandson, etc. 

Trans-mu-ta'tion. (360.) The act of 
changing one impulse into another im- 
pulse. 

Trans-par'ent. Admitting the passage of 
rays of light, so that objects may be seen 
on the other side. 

Tran-sude'. [L. trans, through, and sndo, 
sudatiim, to sweat.] To pass through the 
pores of a substance, as sweat or other 
fluids. 

Trans- verse'. Lying in a cross-direc- 
tion. 

Tra-pe'zi-us. The name of a muscle : — so 
called from its form. 

Tri'ceps. [L. tres, three, and cajnd, a head.] 
A term applied to muscles that have 
three attachments at one extremity. 

Tri-chi'nse Spi-ra'lis. (232.) A species of 
minute worms which work their way 
tlii-ough human muscles, causing pain, 
irritation, and exhaustion. They most 
commonly occur in hog's flesh. 

Tri-cus'pid. (92.) [L. ^/rs, three, and c((,*/)i,s 
a iioint.] The triangular valves in the 
right side of the heart. 

Tri-g:em'i-nus. Tlie triple nerves. The 
trifacial nerve. The branches are oph- 
tli<diiii(\siipra-iiia.rilhn-ii, and itifra-nia.v- 
illani. 

Troch'le-a. [Gr. trocIuTnu a pulley.] A 
pulley-like cartilage, over which the ten- 
don of a muscle of the eye passes. 

Trunk. The principal part of the body, to 
which the limbs are articulated. 

Tu'ber-cle. [L. tidwr, a bunch.] A pim- 
ple, swelling, or tumor on anitnal bodies. 
A morbid iiroduet occurring in certain 
lung diseases. 



366 



GLOSSARY 



Tur'bi-na-ted Bones. [L. hwbo, a top.] The 
convoluted bones of the nostrils. 

Turn'ing. (523.) The German athletic 
exercise drill. 

Tym'pa-num, (433.) [Gr. tumpanon, a 
drum.] The middle ear. 

Ty'phoid.Pe'ver. [Gr. tuplios, stupor, and 
eidos, form.] A fever resembling typhus, 
but having intestinal lesions. 

Ty'ro-sin. (310.) [Gr. iuros, cheese.] A 
product of pancreatic digestion, associ- 
ated with leucin, having white and taste- 
less crystals. It may be made of casein. 

TJl-cer-a'tion. The formation of an ulcer ; 
an ulcer or sore ; a solution of con- 
tinuity. 

Ul'na. [L.] A bone of the forearm. 

tri'nar. Relating to the ulna. 

TJm-bi-li'cus. [L.] The navel. 

TJ-rae'mi-a. (305.) [LVea, a constituent of 
urine, and Gr. haima, blood.] The pres- 
ence of an excess of waste nitrogen com- 
pounds in the blood. 

U-re'ter. [Gr. ourein, to conduct water.] 
The excretory duct of the kidneys. 

U-re'thra. [Gr. ourein, to pass urine.] The 
membranous tube leading from the uri- 
nary bladder. 

TJ'ric, [Gr. ouron, urine.] An acid con- 
tained in urine and in gouty concretions. 

TJ'vu-la. A soft body suspended from the 
palate, near the aperture of the nostrils, 
over the glottis. 

Vac'cine Vi'rus. [L. vacca, a cow, and 
virus, poison.] The material derived from 
heifers for the purpose of vaccination, — 
the great preventive of smallpox. 

Vac'u-um. [L. vacuus, void, empty.] A 
space void of matter. 

Va'g-us, pi Va'gi. (383.) [From vuyo, to i 
wander.] Wandering. The pneumo- 
gastric nerve is called the vagus. j 

Valve. Any membrane, or doubling of i 
any membrane, which prevents fluids I 
from flowing back into the vessels and | 
canals of the animal body. 

Val'vu-lae Con-ni-ven'tes. (2C4.) [L., the ! 
converging folds.] The semilunar folds 
of the mucous membrane of the small : 
intestine. , 



Va'sa Va-so'rum. (lOd.) [L., the vessels 
of the vessels.] The fine blood-vessels 
permeating the coats of the arteries and 
veins. 

Vas'cu-lar. [L. vasculum, a vessel.] Per- 
taining to vessels ; abounding in vessels. 

Va'so-Mo'tor, (134.) [L. vas, a vessel, 
and motor, a mover.] That which causes 
movements or changes in the calibre of 
vessels. 

Vas'tus. [L.] Great; vast: — a term ai> 
plied to some large muscles. 

Vault. The superior arch of the skull. 

Veins. (107.) Vessels that convey blood 
to the heart. 

Ve-na Ca'va. [L., hollow vein.] See 1[ 102. 

Ve'nous. Pertaining to veins. 

Ven-ti-la'tion. (204.) [From L. ventilo, 
ventilatum, to blow, or to fan.] The oper- 
ation of causing the air to pass through 
any place for the purpose of expelling 
impure air. 

Ven'tri-cle. [L. venter, the stomach.] A 
small cavity of the animal body. 

Ver-mic'u-lar. [L. vermiculus, a little 
worm.] Resembling the motions of a 
worm. 

Ver-mi-for'mis. (268.) [L. vermis, a worm, 
and /on)*((, form.] Having the form and 
shape of a worm. 

Ver'te-bra,jjZ.Ver'te-brse. (343.) ['L.verto, 
to turn.] A joint of the spinal column. 

Ver'te-bral. Pertaining to the joints of 
the spinal column. 

Ves'i-cal. [L. ras,a, vessel or tube.] Per- 
taining to the urinary bladder. 

Ves'ti-bule. (435.) [L., a porch of a house.] 
A cavity belonging to the ear. 

Vi-bra'tion. [L. vibi-o, vibratum, to shake.] 
The very rapid movements which 
stretched cords or elastic bodies make 
when oscillating. 

Vil'li, plural of Vil'lus. (264.) The small 
conical projections of the mucous mem- 
brane of the small intestine. 

Vi'rus. [L., poison.] Foul matter of an 
ulcer; poison. 

Vis'ce-ral. [L. viscus, viscej-is, a bowel.] 
Belonging to the viscera, or bowels. 

Vis'u-al. [L. video, visum, to see.] Per- 
taining to, or used in, sight. 

Vi'tal. [L. vita, life.] Pertaining to life. 



GLOSSARY. 



367 



Vit're-ous. (454.) [L. vitrum, glass.] Be- 
longing to glass : — applied to a humor 
of the eye, 

Viv-i-sec'tion. [L. vivus, alive, and seco, 
to cut.] Experiments requiring dis- 
section of living animals to advance 
physiological knowledge. 

"Vo'cal, [L. vox, the voice.] Uttered by 
the voice ; belonging to the vocal appa- 
ratus. 

Vod'ki. An alcoholic intoxicant made 
from the potato by the Russians. 

Vo'lar, [L. vola, the hollow of the hand 
or foot.] Belonging to the palm of the 
hand. 

Vo-li'tion. [L. volo, voJitum, to desire.] The 
act of willing or of choosing. 

Vol-ta'ic. A term applied to the electricity 
evolved by the battery of Volta; the 
constant current. 



Vol'un-ta-ry. [L. voluntas, the will.] 
Acting or moving in obedience to the 
will. 

Vo'mer. [L., a ploughshare.] One of the 
bones of the nose. 

Wa'ter-Bed. A case, or tick, made of 
water-proof cloth filled with water. Such 
a bed affords equable pressure. 

Will. (394.) The faculty or power of 
choosing to do or not to do, to act or not 
to act. 

Wis'dom Teeth. (254.) A name given to 
tlie last grinder teeth. 

Wrist'-Drop. (379.) Loss of power in the 
muscles of the forearm in lead poisoning. 

Zy-go-mat'i-cus. [Gr. zugos, a yoke.] A 
term applied to some muscles of the face, 
from their attachment to the zygoma. 



INDEX. 



Abdomen, 137. 

compression of, 117. 
Aberrations, 265. 

Absorption, 38, 40, 42, 100, 153, 159, 173. 
Accommodation, power of, in the eye, 262, 

mechanism of, 262. 
Acid, butyric, 121. 

hydrochloric, 147. 

lactic, 177. 

margaric, 121. 

oleic, 121. 

palmitic, 121. 
Adenoid tissue, 165. 
Adipose tissue, 29. 
After-images of vision, 267. 
A.ir, composition of, 106. 

contamination of, 110. 

effect of impure, 108. 

impurities, 107, 109. 
Air-cells, 93. 
Air-space, 112. 
Albumen, 121. 

Alcohol, action of, 47, 54, 118, 132, 133, 151, 
102, 172, 181, 189, 222, 309. 

effects on the nerve-centres, 228. 

effects on the vascular system, 84. 

injurious effects, 134. 

not a preventive of disease, 134. 
Alimentary canal, 139. 
Aliments, proteid, 120. 
Amoebue, movements of, 18. 

properties of, 18, 19. 
Anatomy, definition of, 15. 
Aorta, G3. 

Appendages of the eye, 252. 
Acpieous humor, 200. 
Arachnoid, 209. 
Arachnoidcan space, 210. 
Arbor vitre, 207. 
Arteries, distribution of, 60. 

pulmonary, 64. 

renal, 169. 

y 



Arteries, structure of, 65. 

systemic, 64. 

table of, 66. 
Arytenoid cartilage, 284. 
Ascending aorta, 224. 
Asphyxia, 340. 

Silvester method of recovery from, 340. 
Assimilation, 173. 
Astigmatism, 265. 
Audition, 344. 
Auditory canal, 244. 
Auricles of the heart, 59. 
Automatism, 53. 

Bath, Simpson's, 37. 

sponge, 84. 

Turkish, 163. 
Bathing, 44. 

beneficial effects of, 326. 

in disease, 46. 

modes of, 45. 

rules for, 47. 

time for, 46. 
Bed and bed-linen of the sick, 327. 
Bicuspid teeth, 142. 
Bilateral action, 204. 
Bile, its color and effect on fats, 151. 
Bile-duct, 151. 
Binocular vision, 268. 
Bladder, gall, 151. 

urinary, 171. 
Bleeding, or hemorrhage, 334. 

managiMuont of, 335. 
Blind spot, 26(). 
Blood, anin'boid movonionts of, 70. 

change of,' in respiration, 100. 

chemical composition of, 70. 

circulation of, 7:>. 

condition of blood in respiration, 104. 

function of, 72. 

microscoiiic appearance o'(, TO. 

physical appearance oU 6!'. 

ot)9 



370 



INDEX. 



Blood, supply for the brain, 226. 

Blushing, 79. 

Body, co-ordinate movements of, 308. 

suppression of by -motions of, 317. 
Bones, chemical properties of, 296. 

formation, 297. 

microscopic character of, 299. 

number of, 23. 

structure of, 23,294. 

table of, 25. 
Brain, 198. 

culture, 234. 

functions of the inferior parts of, 210. 

functions of the superior parts of, 201 . 

membranes of, 203. 

weight of, 198. 

work, 237. 
Bread, influence of, 227. 
Breathing, afl'ected through the skin by 
cold, 104. 

frequency of, 103. 

through the nostrils, 105. 
Bronchi, 93. 
Bronchia, 93. 
Bunion, 300. 
Burns, treatment of, 339. 

Calcium, 16. 

Callus, 32. 

Canal, alimentary, capacity of, 139. 

lachrymal, 254. 

spinal, 195. 
Capillaries, 64. 

flow of blood in, 81. 

interchanges in, 8:::. 

retardation of flow, 81. 

structure of, 69. 

walls of, 69. 
Carbo-hydrates, or starchy foods, 122. 
Carbolic acid, 337. 
Carbon, 16. 

Carbonic acid gas, 100. 
Cartilage, structure of, 296. 

use of, 299. 
Cartilages of the larynx, 284. 
Casein, 121. 
Cells, ciliated, 50. 

epithelial, 90. 

growth and division, 20. 

nerve, 51. 

physiology of, 51. 

structure of, 19. 



Cellulose, 122. 

Cement, 143. 

Cerebellum, structure of, 207, 209, 211. 

Cerebro-spinal system, 196. 

membranes of, 209. 
Cerebrum, functions of, 203. 

structure of, 199. 
Cliemistry, definition of, 15. 
Chest, capacity of, 95. 
Children, alcoholic effects on, 228. 
Chloral, efi"ects of, 229. 
Chlorine, 16. 
Chordae tendinege, 63. 
Choroidea, 257. 
Chyle, 155. 

movements of, 156. 
Chyme, 153. 
Cilia, 50. 

Ciliary motion, 50. 
Circulation of the blood, 55. 

effects of alcohol on, 84. 

proofs of, 82. 

pulmonic, 74. 

systemic, 74. 
Clothing, adaptation of, 43. 

cleanliness of, 42. 

damp, 42. 

in disease, 43. 

kind of, preferable in the sick-room. 
331. 

night, 41. 

object of, 39. 

water-proof, 41. 

woollen, 83, 163. 
Coagulation of blood, 71. 

how favored, 72. 
Coccyx, 138. 
Cochlea, 247. 
Cocoa, 131. 
Coffee, 131. 
Cold feet, 41. 
Colds, causes of, 80. 
Colloids, 154. 
Colon, 150. 
Color of the arterial blood, 78. 

of the iris, 258. 

of the venous blood, 81. 

sensations of, 266. 
Color-blindness, 267. 
Commissure of the optic nerves, 256. 
Compression of the thorax, 117. 
Cones of the retina, 259. 



INDEX. 



371 



Conjunctiva, 255. 
Constipation, 164. 
Consumption, 115. 
Contractile tissues, 48. 
Contraction, theory of muscular, 54. 
Convolutions, cerebral, 199. 

functions of, 203. 
Convulsions, 221. 
Cooking, 126, 162. 
Corium, 31. 
Cornea, 256. 
Corns, 32. 
Corpora quadrigemina, 200, 206. 

striata, 200, '/05. 
Corpus callosum, 199. 
Corpuscles of the blood, 70. 

action of, lOl. 

chemical composition of, 71. 

origin and function of, 71. 
Cosmetics, 35. 

Cranial nerves, functions of, 215. 
Cuspid teeth, 142. 
Cuticle, 31. 

Dandruff, 36. 

Deglutition, 145. 

Demands of modern life, 314. 

Dentine, 143. 

Dermis, 30. 

Diaphragm, 89. 

Diet and its energy, 178. 

for health, 123. 

tables of, 178. 
Dietetics, 186. 
Diffusion of gases, 99. 
Digestibility of foods, 129, 130. 
Digestion, 152-156. 

summary of, 157. 
Drinks, 328. 

Drowning, prevention from, 341. 
Duct, bile, 151. 

Steno's, 140. 

thoracic, 155. 

Wharton's, 141. 
Duodenum, 148. 
Dura mater, 209. 
Dyspepsia, 157. 

aids to, 162. 

prevention of, 163. 
Dyspnoea, 104. 

Ear, bones of, 245. 
external, 244. 



Ear, foreign bodies in, 341. 

functions of external and middle, 248. 

hygiene of, 274. 

internal, 240. 

middle, 245. 

wax of, 245. 
Education, at home and at school, 235. 
Eggs as a food, 127. 
Elasticity, 148. 
Emetics, 331. 
Enamel, 143. 

End-bulbs of Krause, 268. 
Endocardium, 62. 
Endolymph, 250. 

End-organs of the apparatus of vision, 198, 
258. 

of the auditory nerve, 247. 

of the sense of touch, 268. 

seat of, 272. 
Endurance, physical, 188. 
Energy of the body, 176. 

loss of, 179. 

normal expenditure, 179. 

normal income, 179. 
Epidermis, 30. 
Epiglottis, 92. 
Epithelium, 36. 
Erect posture, 309. 
Ethmoid bone, 194. 
Eustachian tube, 245, 248. 
Excretion, 183. 

integrity of working of the nerve-cen- 
tres dependent upon, 227. 

of saltS; 184. 

of urea, 183. 

of water, 184. 
Exercise, adaptation of, 321. 

conditions for, 318. 

deficiency of, 312. 

in gymnastics, 392. 

kinds of, 320. 

mental, 233. 

amount of, 234. 

object of systematic, 313, 318. 

of the muscles, 232. 
Exner on the rapidity of montal operations, 

205. 
Expiration, 99. 
Eye, 250. 

hygiene of, 276. 

iniperfoctions of, 265. 

munagomont of, in adult p(»rioi1, 279. 



372 



INDEX. 



Eye, management of, in childhood, 276. 

in student period, 277. 
Eyeball, 256. 

foreign bodies on, 342. 
Eyebrows, 252. 
Eyelids, 252. 

function of, 254. 

punctse of, 256. 

Face, bones of the, 193. 
Fascia, 27. 
Fat, 27, 121,174. 
Feet, protection of, 41. 
Fenestra ovalis, 246. 

rotunda, 247. 
Ferments, — saliva, gastric, panci'eatic, and 

intestinal juice, 152. 
Fibre, cardiac, 49. 

gray nerve, 51. 

muscular, 26. 

striped, 48. 

tubular nerve, 51. 

unstrip.ed, 49. 
Fibrin, 70. 

animal and vegetable, 121. 
Fingers, mechanism of the, 282. 
Fish, 127. 
Flesh, 23. 
Fluorine, 16. 
Follicles, hair, 33. 
Food, accessory, 123, 

amount of, 158, 188. 

changes in the digestion of, 152. 

deficiency of, 187. 

excess of, 186. 

for a babe, 328. 

for the sick, 328. 

frequency of taking, 160. 

source of the proteids, 120. 

table of values, 128. 

use of, 119. 

want of, 187. 
Foi-ce of heart-beat, 76. 
Fossse. nasal, 248. 
Fourth ventricle of the brain, 288. 
Fovea centralis, 266. 
Fractured bone, 338. 
Freckle, 31. 

Frequency of heart-beat, 76. 
Fi'ontal bone, 194. 
Frost-bite, treatment of, 342. 
Fruits, value for food, 129. 



Function of inferior parts of brain, 369, 
of superior parts of brain, 2Ul. 

Gall-bladder, 151. 
Ganglion, 53. 
Ganglionic cells, 51. 
Gases, diffusion of, 99. 
Gastric juice, 147. 
Germ-force, 21. 
Glands, adenoid, 168. 

lachrymal, 254. 

lymphatic, 105. 

mesenteric, 155. 

mucous, 04. 

oil, 36. 

palpebral, 254. 

salivary, 144. 

structure of, 139, 

thymus, 169. 
Globulin, 121, 
Glottis, 285. 
Gluten, 121. 
Glycerin, 121. 
Glycogen, 151, 174. 
Grains, food-value of, 128. 
Granules, 16. 
Grape-sugar, 151. 
Gray matter of the spinal cord, 213. 

Haemoglobin, 71, 101. 
Hairs, 33. 

color of, 35. 

structure of, 35. 
Harmonious development, 235, 
Hashish, 230 
Health-diet, 123. 
Hearing, apparatus for, 244. 

how impaired, 275 
Heart, 59. 

acceleration of, 77. 

action of, 76. 

capacity of, 63. 

inhibition of, 77. 

motive power of, 61. 

structure of, 62. 

work of, 76. 
Heat, loss of, 180. 

of the body in different climates, 18L 
in fever, 182. 
in health, 180. 

production of, 175. 

regulation of, 181. 



INDEX. 



373 



Heat, source of, 180. 
Hemiplegia, 221. 
Hemorrhage, or bleeding, 334. 
Hepatic artery and vein, 151. 
Hernia, 343. 

Histology, definition of, 15. 
Home, site of the. 111. 
Hunger, 185. 
Hydro-carbons, 121. 
Hydrogen, 16. 
Hygiene, definition of, 15. 
Hyoid bone, 92. 

Ileum, 148. 

Impulses, nervous, 52, 197. 
mechanism of, 222. 

vital, 198. 
Incisor teeth, 143. 

Income and outcome of the body, 177. 
Incus, 245. 

Indigestion, causes of, 158. 
Infants' food, 328. 
Inheritance, influence of, 224, 229. 
Inhibition, 53. 
Tnnominata, 138. 
Insalivation, 145. 
Insensible perspiration, 37. 
Inspiration, 98. 
Interarticular cartilage, 302. 
Intercostal muscles, 88. 
Intestine, large, 149. 

small, 148. 
Iris, 256, 258. 
Iron, 16. 

Irritable tissues, 48, 
Ivy-poison, remedy for, 344. 

.Taw, lower, 141. 

upper, 141. 
Jejunum, 148. 
Joints, 299, 301. 
Juice, gastric, 147. 

pancreatic, its effect on foods, 151. 
Juices, digestive, 153. 

Kroatin, 177. 

Kidneys, effects of alcohol on, 172. 

functions of, 170. 

structure of, 109. 

Labyrinth, 240. 
liachrymal glands, 254. 
Lacteals, 154. 



Lactic acid, 177. 
Lacunae, 297. 
Laminae, 297. 
Large intestine, 149. 
Larynx, 91, 284. 
Leaping, 311. 
Legumen, 121. 
Lens, crystalline, 260. 

function of, 260. 
Ligaments, 23, 195, 301. 
Light, 44, 261. 
Liver, functions of, 151. 

structure of, 150. 
Lungs, 89. 

structure of, 94. 
Lymph, 167. 

function of, 168. 
Lymphatic vessels, ofiice of, 172. 

structure of, 165. 

Magnesium, 16. 

Maize, 128. 

Malar bones, 25. 

Malleus bone, 245. 

Marrow, 23. 

Mastication, 145. 

Meats, 127. 

Meatus auditorius, 247. 

Media, 260. 

Medicine, how to be given, 328. 

Medulla oblongata, 209, 211. 

Membrana tympani, 245. 

Membrane, fibrous, 30. 

mucous, 94. 

of the eye, 256. 

serous, 90. 
Mesentery, 148. 
Milk as a food element, 125. 

chemical constituents of, 120. 
Molar teeth, 142. 
Motor nerve, 215. 
Mouth, boundaries of, 140. 

its action in digestion, 145. 
IMucous glands, 94. 
Mucus, 94. 
Muscles, 23. 

acti(ni of, 306. 

contraction of, 54. 

effect of exercise on, 311. 

intercostuls, 88. 

object of training the, .324. 

of the eve. 201. 



374 



INDEX. 



Muscles, physiology of, 50. 

table of, 302. 
ISIuscular sense, 271, 
Myopia, 281. 

Nails, 32, 283. 

in-grown, 33. 
Narcotics, 230. 
Nasal passages, 91, 194. 
Nerve-cells and fibres, 51, 197. 

afferent and efferent impulses of, 52. 

function of cells, 197. 

ganglionic cells, 51. 
Nerve-centres, 53, 210. 

co-ordination of, 222. 

spinal, 216. 
Nervous system, 196. 

functions of, 197, 218. 

hygiene of, 223. 

summary of, 218, 220. 

sympathetic or ganglionic, 196. 
Nitrogen, IC. 

Nose, bleeding at the, 338. 
Nucleolus, 20. 
Nucleus, 20. 

Nurse, directions for the, 326, 328. 
Nutrition, 173. 

Occipital bone, 194. 

(Esophagus, movements of, 145. 

Oleic acid, 121. 

Oil glands, 36. 

Oils, from what derived, 121. 

Olfactory lobes, 200, 206, 241. 

Open fire, 113. 

Opium, 230. 

Optic nerve, 256. 

Optic thalami, 200, 205. 

Orbits, 193, 252. 

Organ of Corti, 247. 

Organs of sight, 252. 

Osmosis of liqiiids, 153. 

O.xidation of foods, effect of, 177, 

of wood, 176. 
Oxygen, 16. 

action of, 102, 104. 

its entrance into the blood, 105. 

Palate, 91. 

Pancreas, structure of, 151. 

Papillaj, 31. 

Papillary layer, 31. 

Paralysis, 221. 



Paraplegia, 222. 

Parietal hones, 194. 

Parotid gland, 140. 

Patella, 294. 

Pedun^jles of the brain, 199, 211. 

Pelvis, bony, 138. 

renal, 169. 
Pepsin, 147. 
Peptones, 147, 154. 
Pericardium, 62. 
Perilymph, 250. 
Periosteum, 23, 295. 
Peristaltic action, 149. 
Peritoneum, 138. 
Perspiration, 37. 

Simpson's method of producing, 37. 
Pharynx, 91. 

structure of, 145. 
Phosphorus, 16. 

Physical culture, different systems of, 
314. 

iufliience of, 316. 
Physiology, definition of, 15. 
Pia mater, 209. 
Pigments of the skin, 30. 
Pinna, 244. 

Plasma of the blood, 70, 73. 
Pleura, structure of, 89. 
Poisons and their antidotes, 331. 
Pons Tarolii, 209, 211. 
Portal vein, 64, 151. 
Posture, 322. 
Potassium, 16. 
Poultices, 329. 

Production of heat and energy, 175. 
Proteid compounds, 17. 
Proteids, food-stuffs, 120, 147, 
Protoplasm, properties of, 20, 198, 
Pseudopodia, 18. 
Pulse, 82. 

Pupil of the eye, 257. 
Pylorus, 148. 
Pyramids, renal, 169. 

Quiet in the sick-room, 327. 
Quizzing glass, 282. 

Reaction period, 205. 
Rectum, 150. 
Red corpuscle, 71. 
Reflex action, 52, 212. 
Refraction of light, 261. 



INDEX. 



375 



Reproduction of the amoeba, 18. 
Respiration, abdominal, 96. 

changes in blood, 69, 100. 

changes of air in, 100. 

labored, 98. 

mechanism of, 97. 

of the amoeba, 19. 
Respiratory centre, 103. 
Rest, 238, 319, 326. 
Rete mucosum, 31. 
Retina, 257. 

Rhythm of heart-beat, 78. 
Ribs, 86, 98. 
Rickets, 123, 187. 
Root of the lungs, 94. 
Running, 310. 

Sacrum, 138. 
Saliva, use of, 144. 
Salivary glands, 144. 
Salts as food, 123. 
Sarcolemma, 48. 
Sclerotica, 256. 
Scurvy, 124. 
Sebaceous glands, 36. 
Secretion by the kidneys, 169. 

digestive, 147. 

of the skin, 38. 
Sedatives, 227. 
Semicircular canals, 247. 
Semilunar valves, 60 
Sensation, localization of, 270. 
Sensations of pressure, 269. 

of temperature, 270. 
Sense of equilibrium, 272. 

of touch, 38. 
Sensible perspiration, 37. 
Sensory impulses, 213. 

influences, 309. 

nerve, 214. 
Serum, its chemical composition, 70, 91. 
Sewer-gas, 109. 
Sick-room, selection of, 326, 
Sighing, lot. 
Sight, 252. 
Silicon, 16. 

Simpson's method for sweating, 47. 
Sinuses of Valsalva, 63. 
Skeleton, 23. 
Skin, 30. 

a heat-rogulator, 182. 

functions of, 38. 



Skin, hygiene of, 39. 

papillai-y layer of, 31. 
Skull, bones of, 194. 

arrangement of, 195. 
Sleep, 236. 

when most refreshing, 237. 
Sleeping-room,. 84, 115. 
Smell, 241. 

hygiene of, 274. 

physiology of, 242. 
Sneezing, 86. 
Soaps, 47. 
Sodium, 16. 
Sound, 247, 286. 

articulate, 289. 
Spasm, 221. 
Speech, 289. 
Sphenoid bone, 194. 
Spinal canal, 195. 

cord, 196, 208, 

functions of, 212. 

nerves, 216. 
Spleen, structure of, 168. 
Stapes, 245. 

Starch, food-stuff's, 122. 
Starvation, 188. 
Sternum, 88. 
Stimulants, 130, 227. 
Stomach, function of, 147. 

structure of, 146. 
Striae, 48. 
Stuttering, 290. 
Subarachnoid space, 210. 
Sublingual gland, 144. 
Submaxillary gland, 144. 
Sugars, 122. 
Sulphur, 16, 119. 
Sunstroke, 344. 
Suprarenal bodies, 169. 
Sutures, 194. 
Sweat glands, 36. 

Sympathetic system, functions of, 218. 
Synovia, 300. 
Synovial monibrano, 299. 

Taste, 240. 

physiology of, 240. 

reaction period, 241. 
Tea, 131. 
Tears, 254. 
Teeth. 142. 

caro of, 160. 



376 



INDEX. 



Teeth, effects of bad, 159. 

milk, 143. 
Temperature of the sick-room, 328. 
Temporal bone, 194. 
Tendons, 306. 
Ternary compounds, 17. 
Tetanus, 221. 
Thalami optici, 205. 
Thirst, 185. 
Thoracic duct, 155. 

respiration, 97. 
Thorax, 58. 

enlargement of, 96. 

structure of, 86, 88. 
Thyroid body, 169. 
Tissues, adenoid, 165. 

adipose, 29. 

areolar, 28. 

connective, 28. 

elastic, 28. 

muscular, 48. 

nerve, 48. 

white fibrous, 28. 
Tobacco, 83, 225, 230. 
Tongue, hygiene of, 273. 

structure of, 140. 
Tooth, structure of, 143. 
Touch, 268. 
Trachea, 92. 
Tricuspid valves, 60. 
Tubuli uriniferi, 169. 
Tunics of the eye, 256. 

functions of, 259. 
Tympanum, 245. 

Unit, anatomical, 20. 

of heat, 178. 
Unstriated muscle, 53. 
Unstriped fibre, 49. 
Urea, 151, 171, 173. 
Uric acid, 175. 
Urine, 170, 343. - 
Uvula, 91. 

Vagi nerves, action of, 103. 
Valves in the veins, 68. 

mitral, 61. 

semilunar, 60. 

tricuspid, 60. 
Valvulae conniventes, 148. 
Vasa vasorum, 68. 
Vaso-motor action, 79. 



Veins, 64. 

blood-flow in, 81. 

inferior vena cava, 64. 

portal, 64. 

structure of, 68. 

superior vena cava, 64. 
Velocity of blood-flow in the arteries, 
78. 

of blood-flow in the veins, 81. 
Ventilation, 112, 327. 

effects on the brain, 227. 
Ventricles of the brain, 200. 

of the heart, 59. 

of the larynx, 285. 
Vermiform appendix, 150. 
Vertebra, 86. 

structure of, 86, 194. 
Vertebral column, structure of, 86, 195. 
Vestibule, 247. 
Villi of the intestines, 154. 
Visual sensation, 266. 
Vital capacity of the lungs, 95. 

force, 21. 

impulses, power of, 198. 

knot, 103. 
Vitreous humor, 260. 
Vocal cords, 284. 
Voice, 287. 

hygiene of, 290. 
Volitional impulses, 213. 
Vomiting, nervous mechanism of, 149. 

Walking, 179, 310. 
Want of food, 187. 

of useful employment, effects of, 236. 
Waste products, 183. 
Watcher, duty of, 330. 
Water as food, 124. 

characteristics of good, 124. 

comparative value of, 125. 
Wharton's duct, 141. 
Whispering, 290, 330. 
White corpuscles, 71. 
Winking, 254. 
Worry, 238. 
W^ounds, 334. 

by poisonous serpents, 343. 

flesh, 337. 

from insects, 344. 
Wrist-drop, 35, 221. 

Yawning, 104. 
Yellow spot, 266. 



KEY TO OUTTEE'S 

NEW OUTLINE ZOOLOGICAL CHARTS 



OR 



flOMAN AND COMPARATIVE ANATOMICAL PLATES. 



SUGGESTIONS TO TEACHERS. 

In using these charts, we would suggest that the pupil carefully examine 
the illustrating cuts interspersed with the text in connection with the lesson 
to be recited. The similarity between these and the charts will enable the 
pupil to recite, and the teacher to conduct his recitation from the latter. 

Let a pupil show the situation of an organ, or part, on an anatomical out- 
line chart, and also give its structure, while other members of the class note 
all omissions and misstatements. Another pupil may give the use of that 
organ, and, if necessary, others may give an extended explanation. The 
third may explain the laws on which the health of the part depends, while 
other members of the class may supply what has been omitted. After thus 
presenting the subject in the form of topics, questions may be proposed pro- 
miscuously from each paragraph, and where examples occur in the text let 
other analogous ones be given. 

If the physiology and hygiene of a given subject have not been studiea, 
confine the recitation to those parts only on which the pupil is prepared. 
When practicable, the three departments should be united ; but this can only 
be done when the chapter on the hygiene has been learned, while the physi- 
ology can be united with the anatomy in all chapters upon physiology. 

CHART No. 1. 

OSSEOUS SYSTEM-^HUMAN AND COMPARATIVE. 

A. Holies of the Fluman body. — 1, The frontal bone. 2, The superior max 
"llary (upper jaw-bone). 3, The inferior maxillary (lower jaw-bone). 4, 
The cervical vertebra) (bones of the neck). 5, 6, The lumbar vcrtcbnv (bonoa 
of the loins). 7, The sacrum. S, The tcni])oral bone. 9, The scapuin 
(shoulder-blade). 10, 10, 10, The rib.^. 11. 11. The innoniinata (hip-bonosiV 
12, The huin(MMis (arni-bono). \:\, The radius. 14. The ulna. 15, The car- 
pus (wrist-bones). 16, 1(5, Tho metacarpus (bones of the palm of the hand). 
17, 17, The phalanges (finger-bones ). IS, The femur (thigh-bono). 19. The 



n KEY TO NEW OUTLINE ZOOLOGICAL CHARTS. 

patella (knee-pan). 20, The tibia. 21, The fibula. 22, The tarsus (bonee 
of the instep). 23, 2.3, The metatarsus (bones of the middle of the 
foot). 24, 24, The phalanges (toe-bones), 25, Ligaments of the shoulder. 
26, Ligaments of the elbow. 27, Ligaments of the wrist. 28, Ligaments 
of the hip-joint. 29, Ligaments of the knee. 30, Interosseous membrane. 
31, Ligaments of the ankle. 32, The clavicle (collar-bone). 33, ThesternuoD 
, breast-bone). 

B. Bones of the Cow. — 1, The frontal bone. 2, The upper jaw (supenui 
anaxillary). 3, The lower jaw (inferior maxillary). 4, The cervical vertebra 

bones of the neck). 5, The dorsal vertebrae (bones of the back). 6, 7, The 
lumbar vertebrae. 8, The caudal vertebrae. 9, The scapula. 10, 10, 
The ribs. 11, The innominate bones. 12, The humerus. 13, 14, Tho radiuB 
and ulna. 15, The carpus. 16, The metacarpus. 17, The phalanges. 18, 
The femur. 20, The tibia. 22, The tarsus. 23, The metatarsus. 24, The 
phalanges. 

C. Bones of the Bird. — 1, The cranium. 2, The superior mandible (upper 
jaw). 3, The interior mandible (lower jaw). 4, The cervical vertebrae. 5, 
The dorsal vertebrae. 8, The coccyx. 9, The scapula. 10, The ribs. 11, 
The pelvis. 12, The humerus. 13, 14, The radius and ulna. 15, The car- 
pus. 16, The metacarpus. 17, 17, Phalanges. 18, The femur. 20, The 
tibia. 21, The fibula, 22, 23, The metatarsus. 24, Phalanges. 32, The 
coracoid bone. 33, The clavicle (furcula). 34, The sternum. 

D. Bones of the Tortoise. — 1, The head. 4, The cervical vertebrae. 5, 5, 
6, 6, The dorsal vertebrae and lateral plates. 7, The iliac bones. 8, The 
caudal vertebrae, 9, The scapula. 12, The humerus. 13, 14, The radius 
and ulna. 15, The carpus. 16, 17, Phalanges. 18, The femur. 20, The 
tibia. 21, The fibula. 22, The tarsus. 23, 24, Phalanges. 32, The clavicle. 
33, The coracoid bone. 

E. Bones of the Fish. — 1, The bones of the head. 2, The upper jaw. 3, 
The lower jaw. 4, 5, 6, The dorsal and caudal vertebrae. 8, The first dorsal 
fin. 9, The second dorsal fin. 10, One of the ventral fins. 12, A pectoral 
fin. 18, A ventral fin. 

F. Diagram of an Annulose. — 1, The vascular (blood-vessel) system. 2, 
The digestive system. 3, 3, The ganglia (nervous) system. 4, 4, A series of 
rings of hardened skin which forms an external skeleton. 

GT. Diagram of a Mollusk. — 1, The digestive canal. 2, The heart. 3, 4, 6, 
Ganglia (knots of nervous matter). 

H. Diagram of a Radiate. — (A star-fish). 1, Central aperture. 

CHART No. 2. 

MUSCULAR SYSTEM— HUMAN AND COMPARATIVE. 

A. Muscles of Human Body. — 1, The occipito-frontalis. 2, The orbicularifl 
palpebrarum. 3, The levator labii superioris. 4, The zygomaticus. 5, The 
tnasseter, 6, The orbicularis oris, 7, The temporal. 8, Zygomatici. 9, The 
depressor labii inferioris. 10, The deltoid. 11, 11, The pectoralis major. 
13, The supinator longus. 14, Palmaris longus. 15, The flexor carpi 



KEY TO NEW OUTLINE ZOOLOGICAL CHARTS. lU 

radialis. 16, The obliquus externus. 17, The sartorius. 18, The adductor 
longus. 19, The rectus femoris. 20, The vastus externus. 21, Th*» vastus 
internus. 22, The tendon of the quadriceps extensor. 23, The gastrocnemius 
24, The extensor longus digitorium. 25, The tibialis anticus. 26, The short 
fixtensor muscles of the toes. 27, The tendons of the long extensors. 28, The 
serratus magnus. 29, 29, The external abdominal rings. 30, The saphenous 
opening. 31, 31, 31, 31, The tendons of the wrist and fingers. 32, Tb€ 
sterno-hyoideus. 33, The sterno-cleido-mastoideus. 34, The biceps. 36 
The triceps muscle. 

B. Muscles of the Cow. — 1, The occipito-frontalis. 2, The orbicularis jal 
pebrarum. 3, The masseter. 4, The levator labii inferioris. 5, The platysma 
f, The trapezius. 10, The latissimus dorsi. 11, The pectoralis. 16, 17, The 
external and internal oblique muscle. 18, The opening for the mammary 
aitery and vein (milk-veins). 19, The biceps femoris. 20, 20, 20, The glutei! 
muscles. 33, The masto-humeralis. 

C. Muscles of the Bird. — 1, The occipito-frontalis. 2, The orbicularis pal- 
pebrarum. 5, The masseter. 7, The temporal. 10, The deltoid. 11, The 
pectoralis. 13, The sacro-lumbalis. 14, The extensor carpi ulnaris. 19, The 
vastus externus. 20, The gluteii. 23, The flexor longus digitorium. 24, 
The extensor longus digitorium. 33, The longus colli. 34, The extensor 
plicae alaris. 35, The teres major. 

D. Muscles of the Tortoise. — 1, The digastricus. 10, 10, The deltoides. 
14, The palmaris. 18, The semi-membranosus. 23, The tibialis anticus. 24, 
The gastrocnemius. 28, The sub-coracoideus. 31, 32, The flexores digito- 
rium. 34, 35, The triceps brachii. 

B. Muscles of the Fish. — 1, 2, 3, and a, b, c, represent the zigzag arrange- 
ment of the muscles of the fish (myocomma). 

F. Diagram of an Insect. — 1, The head. 2, The first segment of the chest, 
with the first pair of legs. 3, The second segment, with the second pair of 
legs and the first pair of wings. 4, The third segment, with the third pair 
of legs and second pair of wings. 5, The abdomen without legs. 

CHART No. 3. 
NUTRITIVE SYSTEM— HUMAN AND COMPARATIVE. 

A. The Internal Organs of Man. — 1, The parotid gland. 2, The submax 
illary gland. 3, The sublingual gland. 4, The oesophagus. 5, The larynx 
and trachea. 6, The left lung. 7, The right lung. 8, The heart. 9, The 
veuB cava descendens. 10, The aorta. 11, The pulmonary artery. 12. The 
stomach. 13, 14, The left and right lobe of the liver. 15, 15, 15, The large 
intestine. 16, 16, 16, 16, The small intestine. 17, The diaphragm. 18. The 
g.ill-bladdcr. 

B. Internal Organs of a Goat. — 1, The second stomach (reticulunO. 2, The 
third stomach. 3, The fourth stomach (rennet ). 1. Fold of the mesentery. 5, 
The jejunum. 6, The ileum. 7, The caecum. S. The colon. 9, The right 
kidney. 10, The rectum. 11, 12, Lobes of the liver (turned forward). 13, 
The gall-cjst. 14, Inferior part of abdomen. 15, The omentum. 



IV KEY TO NEW OlJTIJNE ZOOI^OGICAL CHARTS 

C. Organs of a H-in<jr,/ /!.'2'tile. — 1, The ventricle of the heart. 2, 3, The 
auricles of the heart. 4, 5, 6, Blood-vessels. 7, The trachea. 9, 10, 11, The 
liver and its appendages. 12, The stomach. 13, The duodenum. 14, 15, 16, 
The intestines. 17, The cloaca. 18, The caeca. 

D. Diagram of the Organs of a Frog. — 1, The heart. 2, 2, Arches of th« 
ftorta. 3, 3, Pulmonary artery. 4, 4, The pulmonary veins. 6, The stomach. 
%t The digestive canal. 

CHART No. 4. 
DIGESTIVE SYSTEM— HUMAN AND COMPARATIVE. 

A. Digestive Organs of Man. — 1, The upper jaw. 2, The lower jaw. 3, 
The tongue. 4, The hard palate (roof of the mouth). 5, The parotid gland. 
6, The sublingual gland. 7, The larynx. 8, 9, The oesophagus. 10, The 
stomach. 11, 11, The liver. 12, The gaU-bladder. 13, Its duct. 14, The 
duodenum. 15, The pancreas. 16, The spleen. 17, 17, 17, 17, The small 
intestine. IS, The caecum. 19, The appendix vermiformis, 20, 20, The as- 
cending colon. 21, The transverse colon. 22, 22, The descending colon. 
2.3, The sigmoid flexure of the colon. 24, The rectum. 

B. Digestive Organs of a Foiol. — 9, The oesophagus. 8, The crop (inglu- 
vies). T, The second stomach (proventriculus). 10, The gizzard. 11, 11, The 
liver. 12, The gaU-bladder. 13, The bile ducts. 14, 14, 14, 14, The duode- 
num. 15, The pancreas. 16, The caeca (pouches). 17, The large intestine. 
24, The cloaca. 25, The trachea. 

C. Digestive Organs of an Ox. — 1, The oesophagus. 2, 2, The rumen 
(paunch). 3, The second stomach (reticulum). 4, The omasum (maniplies). 
5, The fourth stomach or abomasum (rennet). 6, The duodenum (intestine). 

D. Digestive Organs of an Insect. — 8, The crop. 9, The gullet. 10, The 
gizzard. 14, 14, The chylific (digestive) stomach. 16, 16, Biliary vessels. 
17, The intestine. 18, The renal vessels. 24, The cloaca. 

E. Digestive Organs of the Sicord-Fish.— 11, 11, The liver. 13, The bile 
duct. 16, 16, The caecas (pouches). 17, 17, 17, The intestine. 24, The larjre 
Intestine. 

F Digestive Organs of the Herring. — 1, 1, The air-bladder. 2, The air- 
duct (pneumatic). 9, The oesophagus. 10, The stomach. 16, The caeca 
17, 17, 17, The intestine. 

CHART No. 5 
ABSORPTIVE SYSTEM— HUMAN AND COMPARAliVE. 
A Absorbent Vessels in Man. — 1, 2, 3, 4, Lymphatic vessels and glands ci 
the lower extremities. 5, 6, Inguinal lymphatics and glands. 8, Lymphatic 
vessels of the kidney. 12, The thoracic duct. 10, 10, 10, The intercostal 
lymphatics. 11, The receptaculum chyli. 13, Lymphatics of the neck. 14, 
14, Carotid arteries. 15, Axillary glands. 16, 17, 18, Lymphatics of the 
arm and hand. 19, Lymphatics of the face. 20, The right subclavian vein. 
%l, The junction of the thoracic duct with the left subclavian vein. 



KEY TO NEW OUTLINE ZOOLOGICAL CHAK'TS. V 

B. Section of the Layers of the Skin. — 1, The dermis. 2, 3, The epider 
nais. 4, The rete mucosum. 5, Subcutaneous connective and adipose tissue. 
0, Tactile papillae. 7, Sweat or perspiratory glands. 8, The duct of the 
sweat glands. 9, Spiral passages of the ducts through the epidermis. 10, 
10, The termination of the ducts on the surface of the epidermis. 

C. Section of the Papillae and Glands of the Skin. — 1, 1, 1, 1, Ridges of thft 
outicle (cut vertical). 2, 2, 2, Furrows or wrinkles of the cuticle. 3, The 
epidermis. 4, The rete mucosum. 5, The dermis. 6, 6, 6, The papilloo. 7 
7, Small furrows between the papillae. 8, 8, 8, 8, Deeper furrows betweer 
mch couple of the papillae. 9, Fat cells. 10, 10, 10, The adipose layer, witl 
aumerous fat vesicles. 11, 11, Cellular fibres of the adipose tissue. 12, Two 
hairs. 13, Sweat or perspiratory gland, with its spiral duct. 14, A sudor- 
iferous gland with a duct less spiral. 15, 15, Oil-glands, with ducts opening 
into the sheath of the hair. 



CHART No. 6. 
RESPIRATORY SYSTEM— HUMAN AND COMPARATIVE. 

A. Respiratory Organs of Man. — 1, The larynx. 2, The trachea. 3, The 
right bronchia. 4, The left bronchia. 5, 6, 7, Lobes of the right lung. 8, 

9, Subdivisions of the bronchi or bronchial tubes. 10, 10, 10, 10, Air cells 
11, 11, The diaphragm. 

B. Diagram of the Blood-vessels in Man. — 1, The vena cava descendens. 
2, The vena cava ascendcns. 3, The right ventricle of the heart. 4, The 
left ventricle. 5, 6, The aorta. 7, The pulmonary artery. 8, 9, Divisions 
of the pulmonary artery. 11, Pulmonary vein. 

C. Section of a Quadruped. — 1, The oesophagus. 2, The trachea. 5, 6, 
The lungs. 7, The heart. 8, The stomach, 9, The liver. 10, 10, Intestines. 
il, 11, The diaphragm. 12, 13, The kidney and duct. 14, The brain. 15, 
i6, 15, The spinal cord. 16, 16, 16, The vertebrae. 

D. Section of a Lobule of a Bird's Lung. — 2, A bronchial tube. 3, 4, Divis 
ions of a bronchus that end in sacs. 8, 8, 9, 9, Abdominal air-sacs. 

E. Lung of a Goose. — 2, A bronchus. 3, 4, The bronchial tubes laid open. 

10, 10, Apertures of communication with air-cells. 11, 11, Abdominal bron- 
chial orifices. 

G. Respiratory Organs of the Water-scorpion. — 1, The head. 2, The bast 
oi the first pair of feet. 3, The first ring of the thorax. 4, The base oi 
wings. 5, Base of the second pair of feet. 6, 6, 6, 6, Stigmata (opening ai 
the edge of each joint). 7, 7, 7, 7, Tracheae (air-tubes). S, S, Air-sacs. 

F. Diagram of the Bronchial Leajlets of (he Cod. — 1, A section of a bron- 
chial arch. 2 3, Bronchial leaflets or plates. 

J. DiagraiK ^Z' the Circulation of the /Uood through (he lironvhial Leaflets.— 
1, A section of a bronchial arch. 2, A section of a bronchial artery. 3. 3, 
An arterial branch along the outer margin of the processes, giving off capil- 
lary vessels to the leaflets. 4. A vein that receives the blood from the capil- 
laries of the inner margin ot the process. 5, Bronchial vein. 



VI KEY TO NEW OUTLINE ZOOLOGICAL CHARTS. 

H. A Plexus of Capillary Vessels. 

K. Diagram of the Relative Positions of the Blood-vessels to the Air-cells.— 
I, A bronchial tube communicating with the air-cells, 2, 2, 2. 3, A branch 
of the pulmonary artery containing bluish blood. 4, A branch of a pulmon 
ary vein containing scarlet or purified blood. 

CHART No. 7. 
CIRCULATORY SYSTEM— HUMAN AND COMPARATIVE. 

A. Circulation in Man. — 3, The right ventricle. 4, The right auricle. 6. 
Arch of aorta. 6, Left pulmonary artery. 7, The vena cava descendens. 8^ 
The vena cava ascendens. 9, The descending aorta. 10, The right femoral 
artery. 11, The left femoral vein. 12, The subclavian artery. 13, The sub- 
clavian vein. 14, The jugular vein. l5, The basilic vein. 16, The cephalic 
rein. 17, The kidney. 18, The brachial artery. 19, The ulnar artery. 20 
The radial artery. 21, The anterior tibial artery. 22, The posterior tibia" 
artery. 

B. Diagram of the Circulation iji Reptiles. — 1, Ventricle. 2, 3, Left auri- 
jle. 4, Right auricle. The arrows show the direction of the blood. 

C. Diagram of the Circulation in the Fiih. — 1, The pericardium. 2, Th( 
auricle that receives blood from the body. 3, The ventricle that sends blood 
to the gills. 

D. Diagram of the Heart of Mammals. — 1, The vena cava descendens. 2, 
The vena cava ascendens. 3, The right auricle. 4, The opening between the 
right auricle and right ventricle. 5, The right ventricle. 6, The tricuspid 
valve. 7, The pulmonary artery. 8, 8, Its branches. 9, The semi-lunar 
valves of pulmonary artery. 10, The septum between the two ventricles of 
the heart. 11, 11, The pulmonary veins. 12, The left auricle. 13, The 
opening between the left auricle and the left ventricle. 14, The left ven 
fricle. 15, The mitral valve. 16, The aorta. 17, The semi-lunar valves oi 
the aorta. 

E. The Heart and Arteries of a Snail.— 2, The stomach. 3, 3, The inted 
tine. 5, The heart. 6, Tht aorta. 7, The pulmonary artery. 

CHART No. 8. 
NERVOUS SYSTEM— HUMAN AND COMPARATIVE. 

A. Section of the Human Brain and Spitial Column. — 1, The cerebrum. 8, 
The cerebellum. 3, The medulla oblongata. 4, 4, The medulla spinalis (spinal 
8ord) in the canal formed by the vertebrae of the spinal column. 

B. Back view of the Brain and Nerves in Man. — 1, The cerebrum. 2, The 
uerebellum. 3, The spinal cord. 4, Nerves of the face. 5, Brachial plexus 
of nerves. 6, Internal cutaneous. 7, Ulnar. 8, Musculo-spiraL 9, Cireum- 
(iex. 10, Intercostal. 1 1, Lumbar plexus. 12, Sacral plexus. 13, Posterior 
tibial. 14, Anterior tibial. 15, Popliteal. 16, Scintic. 17, Coccygeal. 

C. The Symjyathetic Nerves. — 1, The renal plexus of nerves. 2, 3, 4, Lom- 
oar ganglion 5, Aortic plexus. 6, Solar plexus. 7, Dorsal ganglia. 8, 9 



KEY TO NEW OUTLINE ZOOLOGICAL CHARTS. 



Vll 



Cardiac nerves. 10, Inferior cervical ganglia. 11, Brachial plexus. 12, 
Superior cervical ganglia. 

D. Base of the Brain of a Horse. — 1, The cerebrum. 2, The optic ganglion. 
3, The cerebellum. 4, The medulla oblongata and spinal cord. 

B. Brain of an Alligator. — 1, The olfactory ganglion. 2, The cerebrum. 
3, The optic ganglion. 4, The cerebellum. 5, The medulla oblongata and 
spinal oord. 

F. Brain of a Bird. — 1, The cerebrum 2, The optic ganglion. 3, Tht 
erebellum. 4, The medulla oblongata. 

G. Brain of a Fish. — 1, The olfactory ganglion. 2, The cerebrum. 3, 
l^he optic ganglion. 4, The cerebellum. 5, The medulla oblongata and spinal 
4ord. 

H. Nervous System of the Beetle. — 1, 1, 2, 2, Nervous ganglions and cords. 
I. Diagram of the Nervous System of the Centipede. — 1, Nervous ganglia. 
J. Diagram of the Nervous System of the Star-Fish. 



CHART No. 9. 
SPECIAL SENSE— HUMAN* AND COMPARATIVE. 

A. The Nervous System of Man, — The convolutions of the large brain (cere 
orum). 2, The lesser brain (cerebellum). 3, The cervical nerves. 4, The 
dorsal nerves. 5, The lumbar nerves. 6, The sciatic. 7, The peroneal nerve. 
8, The posterior tibial nerve. 9, Median nerve. 

B. Section of the Globe of the Eye. — 1, The choroid coat of the eye. 2, Th« 
sclerotic coat. 3, The retina. 4, The cornea. 5, 5, The iris. 6, The pupil. 
8, 9, The chambers of the eye that contain the aqueous humor. 10, The crys- 
talline lens. 11, 11, The vitreous humor. 12, Arteria centralis retinae. 13 
The optic nerve. 

C. Distribution of the Trifacial {fifth pair) Nerve. — 1, The trifacial nerve 
2, A branch that passes to the eye (ophthalmic). 3, A branch distributed to 
the teeth of the upper jaw (superior maxillary). 4, The branch that passe* 
to the tongue (5) and teeth of the lower jaw (the inferior maxillary). 6, The 
gustatory branch. 7, Inferior dental nerve. 

D. Distribution of the Olfactory Nerve. — 1, The olfactory (or nerve of 
■mjell). 2, 2, The fine divisions of this nerve on the membrane of the nose 
I, A branch of the fifth pair (trifacial) nerve. 

E. Front view of the Organ of Hearing. — 1, The auditory canal. 2, Th« 
Irum of the ear (mcmbrana tympani). The chain of bones in the ear (3 
I he malleus. 4, The incus, and, 5, The stapes). 6, The cavity of the tym 
panum. 7, The vestibule. 8,9, 10, The semi-circular canals. 11. 11,12, 
Channels of the cochlea. 13, Cavity in the mastoid portion of temporal bone 
14, The opening from the middle ear to the throat (Eustachian tube'l. 

F. Compound Eye of the Bee. — Its division into facets (highly mag 
nified). 

F. Facets still more highly magnified. 

F. Facets with hairs growing between tbein. 



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